CC130342 Hercules - Epilogue - Flight Safety Investigation Report

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Report / February 21, 2012 / Project number: CC130342 - A Cat

Location: Key West, Florida
Date: 2012-02-21
Status: Investigation Complete

FSIR - download PDF version, 4.58 MB

Epilogue

During a touch and go at Naval Air Station Key West just prior to the aircraft becoming airborne, the Loadmaster, who was seated in the rear of the cargo compartment, heard an electrical buzzing sound and observed an orange jet-like flame shoot across the cargo ramp floor.  He unbuckled his harness and was reaching for the fire extinguisher when an expansive orange fireball erupted, causing him to protect his head with his jacket.  Once the fireball receded, he alerted the crew to the fire and moved forward to escape the heat and smoke.

Concurrent with the fire alert, the aircraft became airborne and reached 10 feet in altitude above the runway.  With sufficient runway remaining, the Flying Pilot landed straight ahead and aggressively stopped the aircraft while the Non-Flying Pilot notified Air Traffic Control.  Once the aircraft came to rest and the engines were shut down, all nine crewmembers quickly egressed and moved upwind of the aircraft.  Crash Fire and Rescue services responded and expeditiously extinguished the fire.  The aircraft was extensively damaged and one crewmember received a minor injury.

The investigation determined that routing and clamping deficiencies in a modification to install ground test connections to the auxiliary hydraulic system, resulted in chafing between the hydraulic pump motor power wire and a pressurized hydraulic flexible hose.  Electrical arcing between the wire and the hose resulted in a pin-hole breach of the flexible hose, release of hydraulic fluid under high pressure, and initiation of the fire.   

Preventive measures included redesign of the modification, as well as changes to the modification process to include specialist review of wiring and hydraulic lines to ensure proper routing, support and protection from chafing, abrasion, harsh environments and damage from anticipated hazards.   Preventive measures also included measures to educate and create awareness of the hazards associated with chafing. 

A number of collateral observations were made and preventive measures recommended, including use of the dual layer principle for aircrew fire protection, policy for maintenance technicians flying as crew members, and improving communication between airworthiness authorities when imposing and lifting operational restrictions.

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CANADIAN FORCES FLIGHT SAFETY INVESTIGATION REPORT (FSIR)

FINAL REPORT

FILE NUMBER:  1010-CC130342 (DFS 2-5)

FSOMS IDENTIFICATION NUMBER:  151543

DATE OF REPORT:  16 December 2015

OCCURRENCE CATEGORY:  "A"

AIRCRAFT TYPE:  CC130 Hercules

AIRCRAFT REGISTRATION NUMBER:  CC130342

DATE OF OCCURRENCE:  21 February 2012

TIME OF OCCURRENCE (L):  08:58 (L)

LOCATION:  Naval Air Station Key West, Florida

OPERATOR:  435 Squadron, 17 Wing

This report was produced under authority of the Minister of National Defence (MND) pursuant to section 4.2 (1)(n) and 4.2 (2) of the Aeronautics Act, and in accordance with A-GA-135-001/AA-001, Flight Safety for the Canadian Forces.

The contents of this report shall only be used for the sole purpose of accident prevention.  This report was released to the public under the authority of the Director of Flight Safety (DFS), National Defence Headquarters, pursuant to powers delegated to him by the MND as the Airworthiness Investigative Authority (AIA) for the Canadian Forces.

SYNOPSIS

During a touch and go at Naval Air Station Key West just prior to the aircraft becoming airborne, the Loadmaster, who was seated in the rear of the cargo compartment, heard an electrical buzzing sound and observed an orange jet-like flame shoot across the cargo ramp floor.  He unbuckled his harness and was reaching for the fire extinguisher when an expansive orange fireball erupted, causing him to protect his head with his jacket.  Once the fireball receded, he alerted the crew to the fire and moved forward to escape the heat and smoke.

Concurrent with the fire alert, the aircraft became airborne and reached 10 feet in altitude above the runway.  With sufficient runway remaining, the Flying Pilot landed straight ahead and aggressively stopped the aircraft while the Non-Flying Pilot notified Air Traffic Control.  Once the aircraft came to rest and the engines were shut down, all nine crewmembers quickly egressed and moved upwind of the aircraft.  Crash Fire and Rescue services responded and expeditiously extinguished the fire.  The aircraft was extensively damaged and one crewmember received a minor injury.

The investigation determined that routing and clamping deficiencies in a modification to install ground test connections to the auxiliary hydraulic system, resulted in chafing between the hydraulic pump motor power wire and a pressurized hydraulic flexible hose.  Electrical arcing between the wire and the hose resulted in a pin-hole breach of the flexible hose, release of hydraulic fluid under high pressure, and initiation of the fire.   

Preventive measures included redesign of the modification, as well as changes to the modification process to include specialist review of wiring and hydraulic lines to ensure proper routing, support and protection from chafing, abrasion, harsh environments and damage from anticipated hazards.   Preventive measures also included measures to educate and create awareness of the hazards associated with chafing. 

A number of collateral observations were made and preventive measures recommended, including use of the dual layer principle for aircrew fire protection, policy for maintenance technicians flying as crew members, and improving communication between airworthiness authorities when imposing and lifting operational restrictions.

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TABLE OF CONTENTS

1.  FACTUAL INFORMATION

2.  ANALYSIS

3.  CONCLUSIONS

4. PREVENTIVE MEASURES

Annex A - Crew Station Diagram

Annex B - Fuselage Station Chart

Annex C - Abbreviations

Annex D - List of Tables and Figures 

1  FACTUAL INFORMATION

1.1  History of the Flight

1.1.1  435 Transport and Rescue (T&R) Squadron (Sqn) was deployed to the Opa-Locka Executive Airport (KOPF) near Miami, Florida in order to provide air-to-air refuelling (AAR) support to CF188 fighter aircraft from 410 Tactical Fighter Squadron which were deployed to Naval Air Station Key West (NASKW).  435 T&R Sqn deployed with Hercules CC130342, configured for AAR operations.  Aircrew proficiency training and check rides were to be conducted concurrent with the AAR sorties.

1.1.2  On 21 February 2012, CC130342 was scheduled to provide AAR support, followed by proficiency training and landing at NASKW to replenish the liquid oxygen (LOX) system.  The crew consisted of the Aircraft Captain (P1), a Level III1] First Officer (FO) acting as the Aircraft Captain (P2), a Level II FO (P3), an Air Combat Systems Officer (ACSO), a Flight Engineer (FE), two Load Masters (LM1 and LM2). Also on-board were two Maintenance Technicians (MT1 and MT2).  The crew conducted their pre-flight tasks and gathered inside the aircraft to conduct their on-board brief (OBB) at 0655 hours (hrs[2]).  The OBB covered information necessary to coordinate their mission activities including a review of the aircraft evacuation plan.  All crewmembers attended the OBB, except for MT2 who was standing-by outside the aircraft ready to remove the power cart after the engines were started. 

1.1.3  At the beginning of the mission the left pilot seat was occupied by P3, the right pilot seat was occupied by P2, and the bench seat was occupied by P1.  The aircraft took off at 0725 hrs and conducted the AAR portion of the mission as planned.  After the AAR, the aircraft proceeded to NASKW and flew a precision approach radar (PAR) to runway 03 followed by a low approach and go-around.  The aircraft then climbed north of NASKW to 5,000 feet (ft) to effect a right seat pilot change where P1 exchanged seats with P2.  The aircraft was then flown back to NASKW where the plan was to conduct a visual approach to runway 07 to a touch and go.  During the final approach segment, P1 asked P3 to aim for the 500 ft touchdown point on the runway.  P3 acknowledged and touched down firmly at the desired touchdown point.  Just prior to take-off, and concurrent with P1’s V1 rotate call, LM1 called urgently over the intercom that there was a fire in the back of the aircraft.  Seeing sufficient runway ahead, P3 reacted immediately to the intercom call as the aircraft became airborne by calling for landing and retarding the power levers to flight idle.  P1 acknowledged P3’s decision and made a radio call to Air Traffic Control (ATC) stating that the aircraft was on fire and that it would land and stop straight ahead in order to evacuate the crew from the aircraft.

1.1.4  In the cargo compartment LM1 occupied the LM seat situated aft of the internal fuselage fuel tank, forward of the left hand (LH) side para door.  LM2 occupied the LM seat just aft of the crew door on the LH side of the aircraft.  MT1 occupied the forward LH middle row troop seat and MT2 occupied the forward right hand (RH) side row troop seat aft of the forward cargo compartment bulkhead at fuselage station (FS) 245.  Annex A provides a diagram of crew stations and Annex B provides a diagram of fuselage stations for ease of reference.

1.1.5  During the touch and go, LM1 heard an electrical buzzing sound to his right and almost immediately saw a bright orange jet-like flame to his right, just above the cabin floor, extending from the vicinity of the auxiliary hydraulic pump across the cargo ramp to the toilet.  LM1 unbuckled his harness and was reaching to his left for the fire extinguisher bottle when an expansive orange coloured fireball from the back of the aircraft enveloped him.  He protected his head by raising the lapel of his Canadian Disruptive Pattern (CADPAT) intermediate weight jacket.  Once the fireball receded, he urgently called over the intercom that there was a fire in the back and rushed to the front of the cargo compartment.

1.1.6  In the cargo compartment, LM2 and MT1 heard the developing situation on the intercom.  They saw an orange flash, followed shortly thereafter by thick black smoke coming rapidly from the back of the aircraft through which there was an orange glow.  MT2 had been asleep for most of the mission, but was awakened by LM2 prior to the first approach.  MT2 was still semi-asleep and not on headset, but was awoken by the smoke and commotion.  During the emergency landing, LM2 shouted instructions to MT1 and MT2 to remain seated with their seat belts fastened until the aircraft came to a stop.  LM2 also located and actively guarded the forward crew door handle, in part to prevent an egress attempt while the aircraft was still moving, and to prepare for rapid evacuation once stopped.

1.1.7  Immediately upon touchdown, P3 selected maximum reverse thrust and maximum anti-skid braking, bringing the aircraft to a stop on the runway centerline approximately 1,500 ft short of the departure end and conducted an emergency shutdown.  Smoke was entering the cockpit and the crew could feel the cabin air temperature rising.  The elapsed time from LM1’s report of fire until the aircraft came to rest was approximately 27 seconds.

1.1.8  LM2 opened the forward crew door and was the first to exit the aircraft.  The rest of the crew exited in a rapid orderly fashion.  The FE exited last after selecting the aircraft battery switch to OFF.

1.1.9  The crew proceeded towards the front of the aircraft and moved upwind along the runway.  They could see smoke billowing out of the aircraft and, shortly thereafter, flames breached the roof of the fuselage near the LH para door.  P1 confirmed that all personnel had evacuated from the aircraft and then directed everyone to move further away, upwind along the runway, approximately 1,000 ft from the aircraft.

1.1.10  The NASKW Crash Fire Rescue (CFR) service was immediately alerted by ATC and arrived on scene within three minutes of aircraft evacuation.  They aggressively attacked the fire from outside the aircraft through the hole in the fuselage roof, knocking it down[3] within 30 seconds.  They next entered the aircraft and suppressed hotspots while ventilating the aircraft for the following 30 minutes.  A total of 1,500 US gallons of water were used.  The aircraft was later towed off the runway to a corner of the main ramp.

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1.2  Injury to Personnel

INJURIESCREWPASSENGERSOTHERSTOTAL
Fatal 0 0 0 0
Serious 0 0 0 0
Minor 1 0 0 1
Nil 6 2 0 8
Total 7 2 0 9

Table 1.  Injuries to Personnel

1.2.1  One LM received a minor injury when he lost his balance during the maximum deceleration abort, but was able to return to flying duties immediately.  The crew were exposed briefly to smoke and fumes but there were no medical signs or symptoms resulting from this exposure. 

1.3  Damage to Aircraft

1.3.1  The fire and heat compromised the ceiling of the aircraft, resulting in an opening above the LH para door, extending from FS717 aft to FS 844, including the loss of a portion of the main frame at FS 737 which joins the fuselage and tail sections.  Internally, the fire and heat caused extensive structural damage to aluminum support structures and flight controls in the aft interior of the aircraft, predominantly on the LH side extending aft from the LH para door. 

Figure 1.     Aircraft Exterior – Damage to Fuselage Ceiling Area near LH Side Para Door

1.3.2  The aircraft interior was subjected to hot gasses and soot from the fire, which became progressively more severe towards the aft of the fuselage. In addition, the interior was exposed to water from the firefighting efforts which was absorbed by exposed fibreglass insulation blankets and trapped in under floor cavities as the drains became clogged with fire debris.  The combination of gasses, soot deposits, water exposure and environmental proximity to ocean salt air resulted in significant surface corrosion to exposed interior metal panels.

1.3.3  The aircraft sustained “A Category” damage as the aircraft was determined to be economically beyond repair. 

1.4  Collateral Damage

1.4.1  There was no reported collateral damage to the NASKW airfield infrastructure. 

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1.5  Personnel Information

 Medical Aircrew Category Time on Duty (hrs)
Day of 
Time of Duty (hrs)
Last 48 hrs 
Flying hrs
Last 24 hrs 
Flying hrs 
Last 48 hrs
Flying hrs
Last 30 days
 
Flying hrs
Grand Total
 P1 valid  valid  3.9  3.9  1.7  1.7 23   5,051
 P2 valid valid 3.9 3.9  1.7  1.7 24  1,475 
 P3 valid  valid 3.9  3.9  1.7 1.7  16  993 
 ACSO  valid valid  3.9 3.9  1.7  1.7  26  950 
 FE  valid valid 3.9  3.9 1.7  1.7  30  6,614 
 LM 1  valid  valid 3.9  3.9 1.7  1.7  38   4,944
 LM 2  valid  valid 3.9  3.9  1.7  1.7  54  2,074 
 MT 1  N/A  N/A 3.9  3.9  N/A  N/A  N/A  N/A 
 MT 2  N/A  N/a 3.9  3.9  N/A  N/A  N/A  N/A 

Table 2.       Personnel Information

1.5.1  P1:  After completing tours at 413 T&R Sqn and 2 Canadian Forces Flight Training School, P1 was posted to 435 Sqn.  He re-qualified on the CC130 aircraft in July 2008 and has been the Sqn Chief Check Pilot since 2009 as well as the 17 Wing Instrument Check Pilot.  His training and check-ride reports consistently showed him to be an above average pilot.

1.5.2  P3:  P3 was a junior CC130 aircraft pilot who started flying the CC130 aircraft in March 2010.  He has shown consistent progress in his training towards his upgrade to aircraft commander.  Prior to joining the Canadian Forces, he graduated from the Aviation Flight Management Program of Confederation College.

1.5.3  LM1:  LM1 was 435 Sqn’s Loadmaster Leader.  Since 1994, he had accumulated 14 years of flying experience on the CC130 aircraft.  He held qualifications in AAR, Search and Rescue (SAR) and Strategic Airlift and his check-ride reports were consistently outstanding.

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1.6  Aircraft Information

General

1.6.1  The CC130 Hercules is a four-engine fixed-wing turboprop aircraft, used for a wide range of missions, including troop transport, tactical airlift, SAR and AAR.  Aircraft CC130342 was taken on strength by the Canadian Armed Forces (CAF) as a Hercules H Model aircraft in April 1991 as part of a five-aircraft procurement.  All five aircraft, including aircraft CC130342, were subsequently modified to the H(T) Model tanker configuration, specifically to conduct AAR operations. 

Maintenance Information

1.6.2  A review of the maintenance records for CC130342 revealed no overdue inspections or time expired items.  Airframe (AF) hours at the time of the accident are provided in Table 3.   

ITEMAF Hrs[4]COMMENTS
AF Hrs  12839.5 AF hrs since new. (Includes time of last flight = 1.7 AF hrs) 
Time since last Periodic Inspection   745.4

 Completed 06 Dec 2010 at 12094.1 AF hrs (Periodic Inspection Interval = 900 AF hrs)

Time since last Supplementary Inspection  158.6  Completed 24 Nov 2011 at 12680.9 AF hrs (Supplementary Inspection Interval - 450 AF hrs) 
Time since last Primary Inspection   43.8 Completed 04 Feb 2012 at 12795.7 AF Hrs (Primary Inspection Interval = 150 AF hrs) 

Table 3.       Airframe Hours Table

Air to Air Refuelling (AAR) System

1.6.3  At the time of the accident, CC130342 was configured with an AAR system which includes an aluminum cylindrical fuselage-mounted fuel tank with dome shaped ends.  The tank is mounted into a cradle and the tank and cradle assembly is secured within the cargo bay using the cargo handling system restraints.  The tank was approximately 19 ft long by 6 ft in diameter and had a capacity of approximately 25,000 pounds (lbs) or 3,600 US gallons.  A review of the daily aircraft maintenance certificate dated 21 February 2012 and the AAR refuelling log determined that the fuel remaining in the internal fuselage fuel tank at the time of accident was approximately 15,000 lbs.

Aircraft Seating

1.6.4  Flight deck seating consists of a left and right seat pilot, an FE seat located between the pilot seats and an ACSO seat located aft and to the right of the FE.  These seats all have four-point harnesses.  Immediately aft of the ACSO station is a bench seat configured with three two-point lap belts.  The bench seat back is located against the forward side of the FS 245 bulkhead.  The flight deck is accessed via a three step ladder from the crew entry door on the forward LH side of the fuselage.

1.6.5  There were two LM seats installed in the cargo compartment, the first located just aft of the forward crew door and the second seat located just forward of the LH para door.  The LM seats are a recent aircraft modification which consists of folding seats with a four point harness. 

1.6.6  The cargo compartment of aircraft CC130342 was configured with side-facing rag and tube style troop seats with two-point lap belts.  The troop seats were installed along the left and right fuselage walls of the aircraft forward and aft of the internal fuselage fuel tank.  In addition, seats were installed back-to-back along the aircraft centerline between FS 245 to FS 330 forward of the internal fuselage fuel tank.  There was a five ft open area from the centerline seat stanchion to the front of the internal fuselage fuel tank (FS 390).  See Annex A for aircraft seating locations.

Oxygen System

1.6.7  The aircraft was equipped with a 25 litre LOX converter shock-mounted on the RH side of the nose wheel well.  The converter supplies gaseous oxygen at 300 pounds per square inch (psi) through aluminum plumbing lines to 10 regulators and four recharging connections.  Six regulators are located in the flight deck and four in the cargo compartment.  Two of the cargo compartment regulators are located just aft of FS 245 with two more at FS 737 just aft of the para doors.  Two recharging hoses, from which portable oxygen bottles can be refilled, are located in the flight deck and two are in the cargo compartment.  Five MA-1 portable oxygen units are provided for personnel to use when moving about the aircraft or in an emergency, three on the flight deck and two in the cargo compartment.  See Annex A for a diagram of oxygen regulator and portable oxygen positions.

1.6.8  Due to the urgency of the situation and the ability to conduct a rapid ground egress, neither aircraft oxygen nor portable oxygen units were used.  The LOX quantity recorded as remaining on the daily aircraft maintenance certificate dated 21 February 2012 prior to the accident flight was seven litres.  The LOX quantity was zero following the accident.  

Aircraft Fire Suppression Systems

1.6.9  There were a total of five portable Halon type fire extinguisher bottles in the aircraft as follows: one bottle in the cockpit, one bottle mounted to the FS 245 bulkhead, one bottle mounted to each of the LH and RH wheel wells, and one bottle mounted aft of the LH para door.  The crew did not attempt to suppress the fire or to use the fire extinguishers.   See Annex A for diagram of fire extinguisher bottle positions. 

Emergency Lighting System

1.6.10  Seven portable battery powered emergency lights were fitted with one at each exit location.  Each light has a three-position switch (ON/OFF/ARM).  The lights can also be controlled via a three-position emergency exit light switch (ARMED/OFF/EXTINGUISH).   When armed, the lights are triggered by a 2.5 g deceleration or a loss of aircraft power.  The emergency lighting system was found activated when fire crews entered the aircraft.

Emergency Alarm Bell

1.6.11  There are four alarm bells located in the cargo compartment, which are controlled by a guarded switch at each of the pilot stations.  They are normally used during a forced landing / ditching emergency to warn personnel in the cargo compartment to adopt the brace position or during a ground evacuation to signal the LMs to commence evacuation of personnel from the aircraft.  The emergency alarm bells were not activated during this accident.

Hydraulic Systems - General

1.6.12  There are three separate hydraulic systems each capable of supplying hydraulic pressure of 3,000 psi which provide the power to operate the aircraft flight controls, flaps, landing gear, wheel brakes, nose gear steering, the cargo door and the ramp.  These three systems are called the booster, utility and auxiliary systems.  Each system is independent of the other in that each system has its own electrically driven hydraulic pump, hydraulic fluid reservoir, valves and associated plumbing.  The hydraulic fluid approved for use on the CC130E/H was MIL-H-5606 (NATO Code H-515).

Auxiliary Hydraulic System - Operation

1.6.13  The auxiliary hydraulic system was the system of interest to this investigation.  It provides hydraulic power for normal operation of the ramp and cargo door, emergency operation of the aircraft main wheel brakes, emergency extension of the nose landing gear, and ground operation and bleeding of the utility hydraulic system.  In accordance with (IAW) the normal landing and take-off checklists, the auxiliary hydraulic system is selected to ON after extending the landing gear on approach, and to OFF after the gear is raised on departure.

1.6.14  The auxiliary hydraulic system is operated from the hydraulic control panel on the co-pilot instrument panel by setting the AUX PUMP indicator switch to the ON position, or from the ramp control panel in the cargo compartment by turning the PUMP switch to ON.  The electric motor that drives the pump operates from three-phase 115/200 volt AC power (Phase A, B and C) derived from the essential alternating current (AC) bus through three 35-ampere circuit breakers, located on the pilot side circuit breaker panel.  Additionally, there is a 28 volt direct current (DC) ramp hydraulic pump control circuit breaker located on the co-pilot’s lower circuit breaker panel connected to the essential DC bus.  None of these circuit breakers were found tripped after the accident.

Auxiliary Hydraulic System - Configuration

1.6.15  The aft LH side of the aircraft fuselage behind the para door is equipped with a support structure that enables the mounting, securing and stowing of the auxiliary hydraulic system components, cargo tie-down stowage racks, tie-down chain stowage boxes, crew drinking containers and the cargo ramp support assembly.  The main components of the auxiliary hydraulic system are located within this support structure.

1.6.16  Three vertical tubular struts, equally spaced at FS 770, FS 792 and FS 814, provide structural support to the area.  Clamps are used as attachment points to mount cross-braces horizontally between each strut as well as linking them to the adjacent extruded ring segments and extruded longeron hard points.  This provides the basis upon which shelves, drip pans and equipment racks are installed. 

1.6.17  The space between the struts located at FS 792 and FS 814 house the auxiliary hydraulic pump and motor assembly and a 20 litre hydraulic reservoir.   The reservoir is attached to the structure by a bracket on the bottom and an adjustable strap on the top.  A sight glass on the reservoir displays the reservoir fluid level.  The motor and pump assembly are mounted on a support bracket tray assembly directly below the auxiliary system reservoir.  Vibration insulators installed between the motor/pump and the support bracket tray help to reduce noise caused by vibration during pump operation.  The auxiliary hydraulic system incorporates modification C-12-130-000/CF-378 (CF-378) to install two ground test connections which are used to facilitate auxiliary hydraulic system flushing (see Figure 2). Modification CF-378 is only applicable to the CC130H fleet.

 Figure 2.     Aircraft Interior – LH Side, Aft of FS 737:  Main Components of the Auxiliary Hydraulic System. 

1.6.18  Three manual shut-off or drain valves in the auxiliary hydraulic system are used to drain the reservoir and the two drip pans.  The drain valves for the reservoir and the hydraulic pump drip pan are normally set to the closed position.  The drain valve for the reservoir drip pan must be lockwired in the open position IAW modification C-12-130-000/CF-694 (CF-694).

Hydraulic System Oil

1.6.19  The aircraft auxiliary hydraulic system specifies the use of Mil-H 5606 hydraulic oil (NATO Code H-515). NYCO HYDRAUNYCOIL FH 51 (5606 type oil) was stored on-board aircraft CC130342 in cans.  The safety data sheet for this oil lists the flashpoint[5] as 95º Celsius or 203ºF.

1.6.20  The hydraulic oil used to service the aircraft in Winnipeg went by the product name SENT-5606, manufactured by Sentinel Canada.  The safety data sheet lists the flashpoint as 225ºF.

1.6.21  Hydraulic samples from the utility and boost system were sent to the Quality Engineering Test Establishment (QETE) for analysis and found to be consistent with 5606 type (H-515) hydraulic oil.  All samples met the specification values for viscosity and flash point.   

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1.7  Meteorological Information

1.7.1  At the time of the accident, the weather was clear and sunny with light winds. The NASKW Meteorological Aviation Report (METAR) actual weather near the time of the accident was as follows:

KNQX 211353Z 06007KT 10SM FEW025 SCT200 23/18 A3016 RMK AO2 SLP213 T02280183

1.7.2  Weather was not a factor in this accident.

1.8  Aids to Navigation

Not applicable.

1.9  Communications

Radio Communications

1.9.1  UHF frequencies in use by ATC were simulcast.  At the time of the accident, the aircrew were using the aircraft’s number two VHF/UHF radio to communicate with tower.  Radio communications were not a factor in this accident.

Airfield Crash Phone

1.9.2  The airfield was served by a crash phone whereby the control tower was able to initiate the emergency response with a single call.  The crash phone was connected to CFR services, Radar, Base Operations, Security/Dispatch, the Station Commanding Officer, the Operations Officer and Operational Maintenance.  Ten seconds after P1 made the distress call, ATC activated the crash phone; 43 seconds later, CFR was en-route to the aircraft.

Intercom System

1.9.3  The intercom system consisted of control boxes at all primary crew stations where the crew could plug in their headsets.  Additional control boxes on board the aircraft are located in the cockpit aft of the LH pilot seat, at the bench seat, and in the cargo compartment.  There were sufficient headsets and intercom boxes for all crew.

1.9.4  LM1 was plugged into the LH hand observer control box located just forward of the LH para door.  All crew except MT2 heard LM1’s initial distress call over the aircraft intercom system where they were immediately alerted to the critical situation that was developing in the back of the aircraft.  LM1’s intercom cord was only long enough to allow him to stay connected to the intercom while he was in the aft half of the cargo compartment.  As LM1 moved forward in the aircraft, he reached the maximum extent of the intercom cord and he unplugged it as he continued towards the forward crew door.  LM1’s follow-on communications were shouted off intercom.

1.10  Aerodrome Information

1.10.1  NASKW, also known as Boca Chica Field, is a modern full service airport operated by the United States Navy.  The airport is configured with three runways.  The accident runway 07/25, is the longest runway at 10,001 ft long by 200 ft wide. 

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1.11  Flight Recorders

General

1.11.1  The aircraft on-board recording systems consisted of a Solid State Flight Data Recorder (SSFDR), a Cockpit Voice Recorder (CVR), and a Load Monitoring System (LMS).

SSFDR

1.11.2  The SSFDR, mounted in the aft section of the aircraft, is powered by 115 volts AC and records the last 25 hours of flight data.  The SSFDR circuit breaker (CB), located on panel 2 row G, was found tripped after the accident.

1.11.3  The SSFDR was found secured to its rack and transported to the National Research Council (NRC) Flight Recorder Playback Center (FRPC) at Ottawa, ON, for download and analysis.  The Weight on Wheels (WOW) channel recorded that the aircraft was on the ground for 18.7s during the touch and go maneuver. The aircraft was airborne for 10.0s and reached a maximum altitude of 10 feet.  SSFDR recording stopped abruptly 1.4s after touchdown.

1.11.4  SSFDR data also recorded an unusual differential cabin pressure rise from its nominal of 0.05 psi to a maximum of 1.92 psi over a period of 12.3 seconds, starting 0.9s prior to take off (weight off wheels), until the SSFDR stopped recording.  The pressure rise was attributed to the hot expanding gasses produced by the fire in the cargo compartment.  No other unusual data was recorded.

CVR

1.11.5  The CVR, mounted in the aft section of the aircraft, is powered by 115 volts AC and records four audio channels and one data channel. The audio channels record the left seat pilot, the right seat pilot, the FE and the cockpit ambient audio via an area microphone.  The fifth channel records duplicate FDR data as provided by the SSFDR.  The CVR records two hours of information, overwriting information with the latest material.  The CVR CB, located on panel 2 row G, was found set in the normal position after the accident.

1.11.6  The CVR was found lying on the ramp floor, still attached to a portion of its rack which had also fallen.  The CVR was transported to the NRC FRPC for download and analysis.  The CVR indicated that LM1 initiated the alert to the aircrew approximately 0.6s prior to WOW switching to AIR. 

1.11.7  The CVR data channel recorded an additional 0.7s of data from the SSFDR after touchdown, during which the onset of propeller reversal of the #2 and #3 engines was recorded.  CVR was found to continue recording for 16.4s after final touchdown until power was lost to the CVR as a result of the emergency shutdown. 

LMS

1.11.8  The LMS monitors, collects and records individual aircraft events and structural information from sensors and other data processing equipment on a continuous flight by flight basis.  No attempt to recover LMS data was made because a download station was not readily available post-accident and sufficient data was available from the SSFDR and CVR for analysis.

1.12  Wreckage and Impact Information

1.12.1  The aircraft remained intact and upright on its landing gear. 

1.13   Medical

1.13.1  Toxicology samples were drawn by the deployed 410 Sqn flight surgeon at the 410 Sqn medical clinic.  The samples were stored overnight by the flight surgeon and shipped to the Armed Forces Medical Examiner System (AFMES) at Dover Air Force Base for analysis.

1.13.2  The toxicology results were negative.  A review of the crew medical records revealed nothing relevant to the flight safety investigation.

1.14  Fire, Explosives Devices, and Munitions

1.14.1  The aircraft suffered severe damage associated with an interior cabin fire.  In general, heat related damage became progressively more severe towards the aft end of the fuselage and was most severe along the LH side and ceiling of the rear ramp area.   

1.14.2  Along the left wall of the ramp in the area of the auxiliary hydraulic pump, the structure and insulation was charred and heavily covered with soot except for specific zones that formed an irregular “V” shaped pattern in the insulation and support structure.  The three aluminum vertical support posts located along the left interior wall at FS 770, FS 792 and FS 814 were partially melted or consumed by the fire in a “V” shaped pattern indicating temperatures in excess of 1250 degrees Fahrenheit (°F).  In addition, the shiny surviving surfaces below the missing segments were indicative of temperatures above 700 °F at the time the fire was extinguished. (See Figure 3).

Figure 3.     Fire Damage Aircraft Interior - LH Side, Aft of Para Door:  Auxiliary Hydraulic System Area

1.14.3  The ceiling of the fuselage suffered severe heat damage and there was an open hole in the ceiling of the aircraft at FS737.  An aluminum oxygen line carrying 300 psi gaseous oxygen from the right side of the fuselage to the LH side oxygen regulator crossed the ceiling just aft of FS737.  The right side of the line was found drooped from the ceiling and the end of the line, when extended, reached just short of the open hole in the ceiling. 

Figure 4.     Fire Damage Aircraft Interior – Ceiling LH Side, Aft of FS 737

1.14.4  The wire flight control cables which were used to control the rudder and the elevator were found separated at the swaged terminal fittings which join the cable segments, and hanging into the cabin near the rear ramp. 

Figure 5.     Fire Damage Aircraft Interior – Looking Aft of FS 737

1.14.5  An extensive amount of soot was produced by the fire which permeated throughout the cargo area and the flight deck.  

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1.15  Survival Aspects

Airfield Crash Fire Rescue (CFR) Response

1.15.1  NASKW CFR was alerted by ATC via the crash phone and within one minute a Crash Truck was dispatched.  Two minutes later, the TA-1500 Crash Truck (CT1) arrived on scene and proceeded to attack the fire from the eight o’clock position (relative to the aircraft) using the turret nozzle to pour water through the hole in the fuselage roof.  CT1 was able to knock down the fire within 30 seconds.  Concurrently, the TA-3000 Crash Truck (CT2) arrived on scene positioned at the 10 o’clock position where two hoses were laid out to the crew door.  After the fire had been knocked down to a more manageable level, two fire fighters with a hose, backed up by an additional two fire fighters with another hose, entered the aircraft through the crew door.  The visibility inside the cargo compartment was zero and the firefighters inside had to move by feel.

1.15.2  The internal fuselage fuel tank was discovered (with unknown contents to the firefighter) and cooled with water before proceeding to attack the remaining hot spots in the rear of the aircraft.  The LH para door was opened and after exiting the aircraft, a fan was placed inside to ventilate the cargo compartment.  Two firefighters proceeded with a hose to the LH para door and continued to suppress any hotspots from the outside.  This continued for 30 minutes before the emergency was secured.  Two crash trucks, one pumper truck, and two command vehicles were utilized.  A total of 1,500 US gallons of water were used.  The aircraft was towed off the runway and parked on a corner of the main ramp.

Figure 6.     CFR Response

Crash Survivability - Egress

1.15.3  Smoke and heat from the fire rapidly increased in intensity from initiation of the fire to the evacuation and there was a marked sense of urgency among the crew to escape.  Non-standard terminology was used to initiate the evacuation and no alarm was sounded, but each crew member understood the severity of the situation and the need to immediately egress the aircraft. 

1.15.4  The two LMs had immediately unstrapped while the aircraft was moving, one to escape the flames and the other to fight the fire; however, it became immediately apparent that the size of the blaze was beyond their capability.  The rapid deceleration of the aircraft during the abort resulted in a minor injury to one of the LMs when he lost his balance.   During the abort, LM2 physically located and held the forward crew door handle, both to ensure rapid egress when the aircraft came to a stop, and also to prevent egress while the aircraft was still airborne or moving.   Each of the flight deck crew unbuckled from their seats once the aircraft stopped and all crew rapidly egressed from the aircraft through the forward crew door.

Aviation Life Support Equipment (ALSE)

1.15.5  435 Sqn Orders at the time stated[6]:  To maximize personal protection from fire, all crewmembers will abide by 1 Canadian Air Division (CAD) Orders, wearing long underwear for all flights, unless excessively hot climatic conditions dictate otherwise.

1.15.6  The majority of the crew were wearing Canadian Forces (CF) nomex flight suits; however, the maintenance technicians were wearing CADPAT clothing.  None of the crew were wearing dual layer clothing below the waist; several were wearing non-issue cotton t-shirts.  LM1 was wearing a CADPAT intermediate weight jacket as an outer layer over his CF flight suit.

1.15.7  Several of the crew considered using an emergency oxygen mask, but the short timeline prompted them to anticipate evacuating from the aircraft and the masks were not used.

1.16  Test and Research Activities

1.16.1  Not applicable.

1.17  Organizational and Management Information

1.17.1  435 Sqn is an integral unit of 17 Wing based at Winnipeg MB.  The Sqn operates five CC130 aircraft in the SAR, AAR and strategic transport roles.  The Sqn has sufficient integral maintenance personnel to conduct all aircraft inspections except for Periodic Inspections, which are contracted to a third line Repair and Overhaul (R&O) contractor.

1.18   Additional Information

History of Modification CF-378 on the CC130 Fleet

1.18.1  Modification EO 05-175B-6A/245 (CF-245) “Installation of Auxiliary Hydraulic System Ground Test Connections” was issued on 25 June 1971 to install two ground test connections for the auxiliary hydraulic system to facilitate flushing, filling and ground testing.  In this modification, the hydraulic pump output is directed to a pressure test connection, located below the pump, before being routed back into the auxiliary hydraulic system.  A return test connection is also provided which is connected to plumbing attached to the bottom of the hydraulic reservoir.  CF-245 was applicable to all CC130E Hercules in the CAF inventory, which included all tail numbers up to and including CC130328. 

1.18.2  In March 1974, the Department of National Defence (DND) procured five CC130H aircraft, CC130329 through CC130333.  However, CF-245 could not be embodied on the CC130H aircraft due to configuration changes in the auxiliary hydraulic system between the CC130E and CC130H variants.  In particular, a change in hydraulic pump, with a different pressurized fluid output location, necessitated changes to the hydraulic line configuration required to embody the test connections.

1.18.3  Modification leaflet CF-378, dated 08 October 1976 was issued to install the ground test connections of the auxiliary hydraulic system on the new CC130H aircraft CC130329 through CC130333.  In the mid-1980’s, four additional CC130H aircraft, CC130334 through CC130337, were procured to replace attrition losses and CF-378 was embodied on these aircraft between September 1986 and June 1987.  A close up view of the CF-378 ground test connections, as installed on aircraft CC130335, is provided at Figure 7.

Figure 7.     CF-378 Auxiliary Hydraulic System Ground Test Connections (Aircraft CC130335)

1.18.4  Modification CF-378 was re-issued on 20 September 1989 “to correct text” of the original modification leaflet and the new leaflet superseded the original.  The re-issued CF-378 leaflet was also converted to bilingual format.  At the time of reissue of CF-378, three of the original five CC130H aircraft had been destroyed in accidents and the modification leaflet was revised to being applicable to CC130332 and CC130333 only.  There was no mention in the re-issued CF-378 leaflet of aircraft CC130334 through CC130337, even though these four aircraft had also been modified IAW CF-378.   The text of the re-issued leaflet contained minor catalogue amendments to the modification parts list, but no retroactive change was required or performed to any of the six CC130H aircraft that had already embodied the modification. 

1.18.5  In 1990, five additional CC130H aircraft, CC130338 through CC130342, were procured which were converted to Model H(T)90 tanker specification.  In 1996, two additional CC130H Model H-30 “stretch” aircraft, CC130343 and CC130344, were procured.  The Weapons System Manager (WSM) subsequently tasked the CC130 third line support contractor to install CF-378 on these five H(T)90 and two H-30 aircraft, while they were at the contractor’s facility undergoing third line periodic maintenance. 

1.18.6  However, the contractor noted that they could not embody modification CF-378 IAW the (re-issued) modification leaflet as the auxiliary hydraulic system on the CC130 H(T) and H-30 aircraft were different than depicted in the modification instruction, due to a larger capacity reservoir and associated plumbing configuration changes on later production H Models.  To facilitate the work, the third line contractor produced a Maintenance Production Permit (MPP) in which a “standard repair” was developed to change the CF-378 modification to accommodate the aircraft configuration.  The WSM approved the MPP and the first aircraft to embody the MPP version of CF-378 was CC130341 in 2001.  A separate, identical MPP was issued and approved for each aircraft embodied.  The modification, as detailed in the MPP, was embodied on the accident aircraft CC130342 on 1 February 2002. 

1.18.7  The original CF-378 modification instruction issued on 8 October 1976 specified the use of a 28.25 inch flexible hydraulic hose assembly, part number (P/N) MS 28762-8-0282, to route pressurized hydraulic fluid from the ground test pressurized connection back to the auxiliary hydraulic system.  The MPP specified the use of a 28.25 inch hose (P/N AE 2460010-H-0282) or a 38 inch hose assembly (P/N MS 28762-8-0380) which was listed as an alternate in the parts manual. The hose found installed on CC130342 post-accident was a 28.25 inch hose manufactured in May 1999.

Flight Safety Occurrence Management System (FSOMS) Review

1.18.8  A review of FSOMS back to 1990 concerning the CC130 auxiliary hydraulic system produced two occurrences of interest as described in the following paragraphs.

1.18.9  FSOMS 123703, Aircraft CC130334, 17 October 2005:  Following an engine run-up, the cargo compartment was found to be filled with mist that smelled like hydraulic fluid, and the cargo floor was soaked with hydraulic fluid.  It was determined that a braided flexible pressure line (NSN: 4730-00-618-3153) coming from the auxiliary hydraulic pump outlet was chafed through after it had made contact with the auxiliary hydraulic pump tray.   Approximately 11 litres of hydraulic fluid had escaped through a pinhole in the line. 

1.18.10  FSOMS 124111, Aircraft CC130340, 17 November 2005: Following an engine run-up, a flexible pressure line (NSN: 4730-00-618-3153) coming from the auxiliary hydraulic pump outlet was found to be rubbing against a support beam, causing the line to rupture. 

Interactive Electronic Technical Manual (IETM) Not Current

1.18.11  An examination of the laptop computer (tool crib number AN-TB1, serial number CF30KQPA5PM) containing the electronic version of the technical documents to be used for aircraft maintenance on aircraft CC130342 while in Florida was loaded with an out-of-date IETM (version 1.80 dated 26 September 2011).  The IETM version that should have been loaded on the laptop was version 1.83 dated 31 January 2012.  There were three versions issued since the one found in use on the deployment.  The versions issued in October, December and January contained numerous amendments.

1.18.12  The accident Sqn has implemented a system whereby a minimum of one technician is assigned the duties of sub-librarian for the deployment, responsible to ensure the latest version of IETM is being used. The relevant instructions in the Manual of Aerospace Procedures were changed to capture the deployable laptops; two current copies of IETM in CD version are to be supplied by the Master Tech Library to the deploying sub-librarian, prior to departure. There is currently no method of updating the deployed IETM in the field. The other CC130 Sqns deploy with hard copies of technical pubs and have similar update limitations.

Aircraft Electrical and Electronic Wiring Technical Orders

1.18.13  Canadian Forces Technical Order (CFTO) C-17-010-002/ME-001, Aircraft Electrical and Electronic Wiring, is one of a series of CFTOs prepared to assist in the general repair and maintenance of aircraft.  This CFTO is issued by Directorate Technical Airworthiness and Engineering Support (DTAES) and the stated purpose is to gather into one reference manual all recommended practices and techniques, standardize these techniques so that electrical installations will be done in a uniform manner, and promote safety by prohibiting unsafe practices.

1.18.14  CFTO C-17-010-002/ME-001, Part 8, Chapter 1 details wiring installation, support and protection practices required for safety of flight and includes guidance and techniques for wire routing and clamping to prevent and/or protect against chafing, abrasion, harsh environments and damage through various mechanical and chemical mechanisms.  Specific routing and clamping instructions are given for scenarios when the distance between the wire and a flammable line (i.e. lines carrying flammable fluid) is less than 152.4 mm (6 in.) and when less than 50.8 mm (2 in.).  The CFTO states that the minimum clearance shall be 12.7 mm (1/2 in.) and includes a CAUTION stating “Do not route any wire so that it can possibly come closer than 12.7 mm (1/2 in.) to a plumbing line.”

1.18.15  In the scenario of a clearance of between 12.7 mm (1/2 in.) and 50.8 mm (2 in.), the wire may be clamped to the plumbing line itself to ensure minimum separation is maintained, provided the plumbing line is not used to support the wire.  Additionally, the CFTO requirements for this scenario include routing of wires on a level with or above the plumbing line, use of a nylon sleeve over the wire bundle, and spacing of clamps to prevent contact of the wire with the plumbing line if the wire is broken at a clamp.

Hydraulic Technical Orders 

1.18.16  CFTO C-12-130-0B0/MF-001 Part 1, Section 2, para 16.e – General Maintenance Information C130 Hydraulic Systems contains instructions for flexible hose installation which states in part:  “Secure the installed hose far enough away from adjacent parts to prevent chafing, wear, or deterioration from heat or oil.”  In addition, the schematic for auxiliary hydraulic system clamp locations contains the following note: “The minimum number of clamps that may be installed on the hydraulic lines are shown.  If the lines are likely to chafe, install additional clamps.”  Of note, the CF-378 modification for the auxiliary hydraulic test connections and plumbing is not shown on this schematic.

1.18.17  CFTO C-12-010-040/TR-010, Aircraft Flexible Hose Standard Manufacture Replacement and Inspection, Part 3 provides guidance for inspection and installation of flexible hose and provides requirements for routing, bend radii, support clamping, chafing and extreme environments.  One requirement is to support flexible hoses at least every 24 inches and that closer supports are preferred.

Flying Orders

1.18.18     The National Defence Flying Orders, B-GA-100-001/AA-001 contains the following directives:

Crew Requirements - General

To act as a crew member of a Canadian Forces (CF) aircraft, personnel shall:

a.       have successfully completed applicable qualifying courses;

b.       be undergoing applicable qualifying courses; or

c.       have appropriate authorization from Commander 1 Cdn Air Div.

All crew members shall have successfully completed aeromedical training in accordance with Canadian Forces Administrative Order 9‑29 and shall have a copy of the valid Certificate of Aeromedical Training.

Crew Clothing and Life Support Equipment

Canadian Forces aircrew flying Canadian Forces aircraft shall wear clothing and use life‑support equipment approved by the Commander 1 Cdn Air Div.

Crew Briefings

Prior to commencing the assigned flight, the aircraft commander and/or formation leader shall ensure that all members of the aircraft crew and/or formation are adequately briefed on all factors that may affect safety or completion of the assigned duty.

Passenger Briefings

Before commencing the assigned flight, the aircraft commander shall ensure that all passengers are briefed regarding the proposed flight.  Verbal briefings may be supplemented by printed information guides.  Regardless of the communication medium employed, briefings shall include, but need not be limited to:

a.       procedures to be followed in the event of an emergency;

b.       use location and operation of life support systems and equipment; and

c.       any precautions and/or restrictions to be observed.

1.18.19  Flying Operations Manual (FOM), Annex 2.2.1.1.B contains Minimum Crew Requirements for various missions for a number of RCAF fleets.   For the CC-130H conducting  AAR missions, the minimum crew is one AC, one FO, one ACSO, one FE, one LM plus one additional mission qualified LM or FE to act as a second observer.  For Contingency Operations where crewing is an issue, the requirement for the second observer can be waived by the Unit Commanding Officer and single hose operations must be conducted.

1.18.20  The FOM Annex 2.2.1.1.B also provides direction for the carriage of technicians as crew members on board a number of RCAF transport aircraft including the CC-130J Hercules, CC-177 Globe Master, CC-150 Polaris and CC-144 Challenger aircraft.  In general, the FOM allows for the carriage of technicians as crew under defined circumstances for specific missions.  However, the FOM does not specify the carriage of technicians as crew members for flights/missions on the CC-130H Hercules aircraft

1.18.21  The FOM Training and Operational Flights – Passenger Approval Authority (Annex 2.5.3.2.B) allows for carriage of passengers during AAR missions with the proviso:  “For AAR operations and training, duty passengers may be carried on missions provided sufficient qualified crewmembers are available to supervise, receiver conversion training is not scheduled to take place, and passenger approval has been obtained by the appropriate approval authority as per the Familiarization Flights –  Flights – Passenger Approval Authority table (Table 2.5.3.2.A.1).

1.18.22  Neither the National Defence Flying Orders nor the FOM specifically addresses the training, clothing, life support equipment or briefing requirements for technicians when carried as crew members.

Emergency/Abnormal Procedures General

1.18.23  CFTO C-12-130-000/MB-001 Part 3, Section 1, para 1 introduces the overall philosophy and guidance to crews when confronted with emergency or abnormal situations which states in part: “Emergency operating procedures cover critical situations where immediate initial action is required and there is no time to refer to a checklist.”  There is also acknowledgement that “Procedures are not available for all situations that may be encountered; however, good judgment and professionalism must prevail. In all cases, the Aircraft Captain will decide if an action, whether published or recommended, will be carried out. Regardless of the specific emergency or abnormality encountered, do the following:

a.     Maintain aircraft control;

b.     Silence any aural warning;

c.     Identify the emergency and confirm the location; and

d.     Take appropriate, corrective action.”

1.19   Useful or Effective Investigation Techniques

Not applicable.

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2  ANALYSIS

2.1  General

2.1.1  The investigation initially focussed on the technical determination of the source of ignition and fuel for the fire.  The investigation determined that chafing and arcing occurred between a hydraulic line and a power cable.  The hydraulic line was part of a modification to provide ground test connections for the auxiliary hydraulic system. The investigation determined that a series of deficiencies in the modification and its approval process, as well as its installation and in-service maintenance practices were directly causal to the fire.     

2.1.2  The investigation also examined the aircrew reaction to the emergency, aircrew adherence to the dual layer principle, policy on carrying technicians as aircrew, and communication issues related to imposing and lifting of the operational pause.

2.2  Technical Investigation

QETE Examination

2.2.1  A QETE technical investigator was assigned to the on-site investigation team to ensure the preservation of physical evidence and its removal from the aircraft for further analysis.  The V-Shaped fire damage pattern, centered on the three vertical support posts along the left interior wall, aft of the para door (see Section 1.14, Figure 3), indicated that the heat intensity of the fire was greatest near FS 792.  In addition, there was an eyewitness account of an initial jet of flame from the vicinity of the auxiliary hydraulic pump area extending across the floor of the ramp.  Based on these indicators, the technical investigation examined all auxiliary hydraulic system components to search for a potential initiation point for the fire. 

2.2.2  During the on-site investigation, a flexible hydraulic hose assembly (P/N AE 2460010-H-0282) was found to be in contact with the hydraulic pump motor power cable.  The flexible hydraulic hose assembly was part of CC130 modification CF-378, “Installation of Auxiliary Hydraulic System Ground Test Connections” and was the 28.25 inch steel braided hydraulic line used to route pressurized hydraulic fluid from the auxiliary hydraulic test connection to the auxiliary hydraulic system.

Figure 8.  View of Flexible Hydraulic Hose Assembly & Power Cable (Aircraft CC130342)

Figure 9. Flexible Hydraulic Hose Assembly and Power Cable below Cannon Plug

Figure 10.  Close-up of Power Cable and Flexible Hydraulic Hose Assembly in Contact

2.2.3  A number of auxiliary hydraulic system components were removed from the aircraft and sent to QETE for further examination.  Parts removed included the ground test check out valve, the auxiliary hydraulic system reservoir, hydraulic pump and motor, filters, plumbing and electrical components. 

2.2.4  Examination of the hydraulic hose at QETE revealed there was a 2 mm diameter hole in the stainless steel braiding, at the site where it was found in contact with the hydraulic pump motor power cable.  An air test at 0.5 psi indicated the wall of the inner hose was breached at this location.  Examination of the hose braid indicated deposits of copper and tin consistent with the material in the auxiliary hydraulic motor power cable. 

2.2.5  Examination of the hydraulic pump power motor cable revealed broken wire strands on the B Phase wire that had a common separation point.  The wire strand ends were tapered and distorted or rounded in appearance and examination by scanning electron microscope revealed that some of the wire strand material was missing.  The location of the wire damage was consistent with the contact point to the flexible hydraulic hose.

Figure 11.  Flexible Hydraulic Hose Assembly after Removal (length:  28.25 inches)

Figure 12.  Close-up of Location of Breach in Flexible Hydraulic Hose Assembly Line

2.2.6  When hydraulic fluid is released under pressure from a small orifice, an atomized spray of oil droplets is produced that may extend as far as 10m from the break. This atomized spray can be readily ignited by open flames, hot surfaces or electrical arcing and the resulting fire is usually torch-like, with a very high heat release rate. [7]   The initial jet of orange flame across the ramp floor as described by LM1 was consistent with an arcing event igniting an atomized spray of hydraulic fluid.

2.2.7  However, for the fire to propagate back to the breach in the line and stabilize, the oil flow rate and droplet size must be within certain parameters.  It is likely that after the initial jet of orange flame, the flame self-extinguished.  However, hydraulic fluid continued to spray and atomize under high pressure from the leak, dispersing as a fine mist within the cargo ramp area.  FSOMS 123703 is a previous example of how a pin-hole leak in a pressurized hydraulic hose resulted in the cargo area of the CC130 being filled with a mist of hydraulic fluid.  It is likely that a second arcing event ignited this rapidly expanding cloud of hydraulic mist, resulting in the subsequent orange fireball from the ramp area.

2.2.8  Secondary combustion of material then likely occurred, which was sustained by hydraulic fluid continuing to atomize and burn, and was accelerated by internal airflow patterns and by sources of pure oxygen.  Of particular note, the aluminum tubing carrying gaseous oxygen to the regulator at FS737 just aft of the para door crosses the ceiling in the vicinity of the main frame at FS737.  Aluminum melts at a relatively low temperature of approximately 660 degrees Celsius (ºC).   The high temperature of the secondary fire likely consumed the oxygen line, allowing gaseous oxygen to escape.  This breach of the oxygen line would have greatly intensified the fire until the gaseous oxygen had been depleted, resulting in the rapid burn through of the aft fuselage ceiling.   

2.2.9  The technical investigation also noted that the circuit breakers for the auxiliary hydraulic pump motor did not open during the accident.  The circuit breakers are an older bi-metallic thermal activation type (MS25244), which are not designed to respond to short duration arcing events[8].  As a result, power continued to be supplied to the pump motor, creating the potential for multiple arcing events.

2.2.10  Based on the physical evidence, the QETE investigation concluded that the stainless steel outer braid of the pressurized hydraulic flex hose had come into contact with the auxiliary pump motor power supply wiring, chafing the wire insulation and exposing the wire.  An electrical arcing event then occurred between the exposed auxiliary hydraulic system pump motor electrical harness B Phase wire and the auxiliary hydraulic flexible hose that created a hole in the hose, leading to a leak of high pressure hydraulic fluid and subsequent ignition by electrical arcing.

Related Flight Safety Occurrence:  FSOMS 151598

2.2.11  On 24 February 2012, an unofficial inspection by a squadron member at 435 Sqn identified three CC130 aircraft, CC130305, CC130338 and CC130341, with chafed auxiliary hydraulic motor power cables at the location where the power cable and the auxiliary hydraulic system flexible hose assembly made contact.  This finding was made prior to the QETE discovery on the accident aircraft and resulted in the squadron member receiving a “For Pro” Flight Safety award.

2.2.12  The photos taken on CC130341 (Figures 13 and 14) show the auxiliary hydraulic system in a similar condition to that found on the accident aircraft.  Further, the photos show that an unsuccessful attempt was made to protect the power cable by wrapping it with black tape. This condition is unacceptable IAW CFTO C-17-010-002/ME-001, Part 8, Chapter 1 and was in a location that could have been easily detected by visual inspection.

Figure 13.  CC130341 (24 February 2012):  Chafing between Hydraulic Pump Motor Power Cable and Flexible Hydraulic Hose Assembly

Figure 14.    CC130341 (24 February 2012):   Close-up of Chafing between Hydraulic Pump Motor Power Cable and Flexible Hydraulic Hose Assembly   

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2.3  Review of modification CF-378

General

2.3.1  The flexible hydraulic hose assembly that was breached in this accident was part of modification CF-378 as installed by the MPP.  A full review of the MPP installation was undertaken, with particular focus on differences in configuration between the MPP and the original CF-378 modification leaflet. 

Maintenance Production Permit (MPP)

2.3.2  The first aircraft to be fitted with modification CF-378 using the MPP was CC130341.  While attempting to fit CF-378, the contractor had difficulty in implementing the modification in accordance with the modification leaflet.  The contractor developed new routing for the hydraulic lines to “meet the intent” of modification CF-378, and raised and staffed a MPP to embody the revised configuration as a “standard repair”.  The MPP stated that the discrepancy was due to “the hydraulic system on 130341 is different than that installed on 130332 and/or 130333”. 

2.3.3  The contractor submitted the MPP to the Life Cycle Material Manager (LCMM) with the instruction to “treat as urgent”, as flight test of the aircraft was scheduled for the following week.  The date of this MPP request was 30 June 2000, the Friday before the Canada Day long weekend.  At this point, the test connections had already been installed IAW the MPP and the MPP stated that “the existing installation needs to be documented because this installation is what should be completed for the other H(T)90 model aircraft”.

2.3.4  The contractor conveyed a sense of urgency to the LCMM to conduct the review and the LCMM relayed this sense of urgency to a member of the Director of Technical Airworthiness (DTA) staff who was requested to review and comment on the MPP.  The DTA staff member concurred with the work procedure and engineering disposition given in the MPP on 04 July 2000, the first day back to work after the long weekend.  The LCMM signed the DND approval block of the contractor’s MPP form and faxed the form back to the contractor on 06 July 2000.  No evidence was found in the MPP documentation as to the extent of the DTA or LCMM review conducted. 

2.3.5  After approval by the CC130 LCMM, the MPP was approved for embodiment on CC130341 and subsequently used to modify all five H(T)90 and both H-30 variant CC130 aircraft.  A new modification leaflet was not issued; however, the revised configuration was documented in the approved parts manual C-12-130-0B0/MY-001, Figure 2-3-3. 

2.3.6  To better understand the difficulty experienced by the contractor in implementing CF-378, a review was conducted of the auxiliary hydraulic system differences between the various models of CC130H aircraft.  The auxiliary hydraulic pump and mounting location was found to be identical across all models of CC130H aircraft, indicating no change was required to the plumbing used to connect the pressurized hydraulic test connection.  In addition, while there were differences in plumbing associated with a different hydraulic reservoir installed in the HT(90) and H-30, the point at which the return test connection interfaced with the auxiliary hydraulic system remained the same.

2.3.7  The investigation noted that the location of the support bracket for the hydraulic test connections was different between earlier H model aircraft and the MPP embodied H(T)90 and H-30 model aircraft.  This support bracket is located underneath the auxiliary hydraulic pump tray.  The MPP stated “locate bracket so that cut-out in bracket assy clears FWD INBD pump mount” and also directed that the bracket assy be located in-board so that it sat flush against the in-board lip of the tray.  By contrast, the original CF-378 detailed that the test connection support bracket was to be located 2 ½  inches from the forward edge of the tray and 5 inches from the in-board lip of the tray.

Figure 15.  Comparison of CF-378 installations:  Left - Installed using original CF-378 modification leaflet (CC130335);  and Right - Installed using MPP (CC130344)

2.3.8  The change in mounting location of the support bracket necessitated a series of configuration and hydraulic plumbing changes to accommodate the new position of the test connections as follows:

a.  The 20 inch pressurized hydraulic hose from the pump outlet had to span an extra 5 inches length, changing its natural routing and creating greater potential of chafing against the back edge of the pump tray and against the electrical power supply wiring for the pump.  There was no change to the length of this hose in the MPP.

b.  The 28.25 inch hose from the pressurized test connection to the aircraft system also had to span an extra 5 inches, also changing its natural routing and creating greater potential of chafing against the back edge of the pump tray and the electrical power supply wiring for the pump.  This hose was lengthened from 28.25 inches to 38.25 inches in the MPP.

c.  The return test connection had a five inch rigid tube extension to compensate for the five inch in-board change in mounting location.  However, instead of turning forward to connect to the hydraulic plumbing in the manner specified by CF-378, the line continued outboard to the fuselage wall, where it was in contact with the wall insulation blankets as it ascended to a new connection point.

d.  The test connections were now physically protruding slightly into the cabin area

2.3.9  The investigation determined that the change in mounting location of the ground test connection support bracket made installation of CF-378 IAW the modification leaflet instructions impossible and was likely the reason that the contractor had difficult in installing CF-378.  Furthermore, the investigation concluded that it would have been possible to install CF-378 as specified in the original CF-378 modification leaflet on the H(T)90 and H-30 model aircraft, in spite of differences in the auxiliary hydraulic systems for these aircraft, had the bracket been placed correctly.  The end result was that a different configuration of modification CF-378 was applicable to the H(T)90 and H-30 model aircraft, with a revised bracket mounting location, longer hose required from the pressurized test connection to the aircraft system and revised plumbing from the return test connection.

2.3.10  The investigation then focussed on why the contractor had changed the location of the bracket.  A comparison of the original and re-issued CF-378 modification leaflets revealed that the installation drawing, provided as Figure 2, had been converted from three orthographic views from the front, bottom and side (views A, B and C) in the original CF-378 leaflet, to a single three-dimension isometric view in the re-issued CF-378 leaflet.  However, the detail information placing the support bracket 2 ½ inches from the forward edge of the tray and 5 inches in-board was omitted in the re-issued CF-378 leaflet. 

Figure 16.  Comparison of CF-378, Figure 2 Bracket Installation – Original CF-378 showing bracket mounting locations.

Figure 17.   Comparison of CF-378, Figure 2 Bracket Installation – Re-issued CF-378

2.3.11  Both the original and re-issued modification leaflet CF-378, Figure 6 provided a drawing of the test connection installation.  The CF-378 modification documentation folder was found to contain a photograph of the original prototype installation which was used to create this drawing.  The photograph shows that the correct placement of the bracket was to be placed outboard of the drain channel for pump tray.  However, in converting from the photograph to the drawing, details of the drain channel and forward in-board mount were omitted, creating an ambiguity with respect to the correct placement of the bracket, in that it appears that the bracket is placed along the in-board edge of the tray. 

Figure 18. Comparison of CF-378, Figure 6 Bracket Installation – Original Photograph (left) and Modification Leaflet Drawing (right)

2.3.12  The investigation concluded that the absence of placement information in Figure 2 of the re-issued CF-378 leaflet, combined with the ambiguity created by the Figure 6 drawing, likely resulted in the contractor misinterpreting the correct placement of the support bracket as being along the in-board edge of the pump tray.  This led to the contractor placing the support bracket five inches in-board of its intended location, leading to the series of plumbing configuration changes as detailed in para 2.3.8. 

Deficiencies of the MPP Installation Process

2.3.13  The changes in the hydraulic test connection location and plumbing arrangement were significant enough that they should have been dealt with as a new modification instead of a standard repair.  In effect, the urgent MPP, approved as a standard repair, short-circuited the modification process and resulted in an insufficient review of the design changes proposed.  In particular, the incorrect location of the test connection bracket was not detected and effects of numerous configuration changes do not appear to have been fully considered.

2.3.14  The use of the standard repair process also resulted in deficiencies in the technical documentation, in that the parts used for the MPP were listed as alternate parts without specifying the configuration to which they applied (i.e. MPP or CF-378).  In particular, the pressurized hydraulic hose leading from the test connections to the hydraulic system was lengthened from 28.25 inches to 38.25 inches in the MPP.  This longer hose was included in the approved parts list as an alternate part number, but with no explanation that the longer hose should have been applicable only to the H(T)90 and H-30 aircraft which had embodied modification CF-378 IAW the MPP.  

2.3.15  The investigation looked at all seven aircraft which had embodied modification CF-378 IAW the MPP which revealed that all aircraft had the shorter 28.25 inch hydraulic hose installed.  In addition, the manufacture dates of five of these hoses were prior to the MPP installation date.  While it was not possible to conclusively determine if the initial installations by the contractor used the longer (alternate p/n) or shorter (primary p/n) hydraulic line, the manufacture dates suggest that at least some, if not all of these five aircraft could have been initially installed by the contractor with the shorter line.  In addition, the manufacture date of the shorter hose installed on CC130341, the first installation upon which the MPP was approved, was found to be January 2004, which was after the modification embodiment in July 2000, indicating the longer hose had been replaced with the shorter hose a number of years after initial installation.  The investigation concluded that the lack of appropriate documentation resulted in the shorter line being installed on all aircraft, either initially or in-service, which although listed as the primary part, was not intended to be applicable to these installations.  As previously stated, the shorter line in conjunction with the incorrect test connection bracket location would have changed the routing, bringing it closer to the back edge of the pump motor tray where it was more susceptible to chafing with the tray edge and the motor power wire. 

2.3.16  The investigation did not look at how many other modifications were implemented using the MPP process by the contractor.  A full airworthiness review of contractor MPPs for all H(T)90 and H-30 model aircraft should be conducted to ensure that all modifications have been reviewed for airworthiness and configuration control issues and that they have been properly documented.

Rubbing of Pressurized Line on Shelf Support Bracket

2.3.17  A review of FSOMS back to 1990 concerning the CC130 auxiliary hydraulic system revealed two separate occurrences of the rupture of the 20 inch flexible hydraulic hose associated with modification CF-378 leading from the pump outlet to the pressurized test connection.  FSOMS 123703 (17 Oct 2005) states that “during an engine run-up, the cargo compartment of CC130334 was found to be “filled with mist and smelled like hydraulic fluid” and “the cargo floor was soaked with hydraulic fluid”.  In that occurrence, the source of the leak was found to be the 28.25 inch braided line from the CF-378 pressurized test connection that was chafing against the auxiliary pump tray.  The tray was found to have a relief hole/slot cut into the back edge and the corner of the cut-out had caused the rupture in the line, allowing 11 litres of pressurized hydraulic fluid to be sprayed out into the cargo compartment. 

2.3.18  In FSOMS 123703, it was thought that the tray had been modified without authorization and the preventive measure was to brief personnel on the hazards of making unauthorized modifications.  However, on 04 May 2012, investigators were examining CC130334 at 8 Wing Trenton while investigating modification CF-378 and noticed that the “cut-out” still existed on the tray, nearly seven years later (see figure 19).  Additional examination revealed that both the tray and the shelf support bracket had been subject to abrasion by the braided steel hydraulic line.  The investigation concluded that it was possible that the “unauthorized modification” cause factor in FSOMS 123703 was in fact the result of long-term chafing of the steel braided line against the aluminum alloy tray and shelf support.

Figure 19.   CC130334 – Chafing in tray and shelf support bracket related to FSOMS 123703 – Photos taken  04 May 2012 (left) and 29 June 2012 (right)  

2.3.19  A nearly identical occurrence was reported at FSOMS 124111 (17 Nov 2005) where the same pressure line had rubbed against the shelf support bracket on CC130340, causing the line to rupture.  The investigation also observed that the shelf support bracket on aircraft CC130319 (E-Model) was in physical contact with the 28.25 inch pressurized line leading from the pressurized test connection from modification CF-245.  The wear pattern and subsequent overpainting on the bracket indicated it had likely been worn down by the pressurized line at some point in the past.  These findings indicate that the rubbing/chafing of the pressurized lines leading to/from the test connection fitting against the shelf support and aft outboard edge of the tray is an ongoing hazard associated with modifications CF-245 and CF-378.

Routing and Clamping Deficiencies in the Modification Leaflet

2.3.20  The CF-378 modification leaflet provides instructions for positioning of hydraulic fittings to provide a better alignment of the hydraulic lines.  However, the CF-378 modification leaflet does not contain adequate provisions for the routing and clamping of hydraulic hoses to prevent chafing and wear.  Flexible hoses can change position when pressurized and CFTO C-12-010-040/TR-010, states that flexible hoses should be supported at least every 24 inches, and that closer supports are preferred.  Modification CF-378 introduced a 28.25 inch pressurized hydraulic line that was lengthened by the MPP to 38.25 inches; however, no supports were specified in either CF-378 or the MPP. 

2.3.21  In addition, the CF-378 modification leaflet does not provide instructions for clamping of the auxiliary pump motor power wire to maintain the minimum separation with the new hydraulic routing underneath the tray.  In practice, incorrect attempts to prevent chafing were observed including the use of electrical tape and/or plastic sheathing being commonly used to wrap the pump motor wire to prevent it from being chafed.  

2.3.22  Of note, aircraft CC130335 was observed with the auxiliary pump power wire separated from the flexible hydraulic hose assembly by means of a stand-off clamp to maintain a ½ inch separation distance (see Figure 20).  This clamping method is detailed in CFTO C-17-010-002/ME-001, Figure 8-1-13 as a “secondary alternate installation” and shows that in spite of design issues identified with this modification, proper routing and clamping can be an effective mitigation in maintaining a safe separation distance between these components.

Figure 20.    Example of “secondary alternative clamping” to provide positive separation between auxiliary pump power wire and flexible hydraulic pressure line (CC130335, 8 Wing Trenton, 26 April 2012)

2.3.23  The investigation concluded that neither the flex hose nor the wire bundle was adequately clamped to ensure separation of the wire bundle from the flammable line in contravention of CFTO C-17-010-002/ME-001 and CFTO C-12-010-040/TR-010.  Detailed routing and clamping instructions are required to ensure the pressurized lines leading to/from the pressurized test connections are secured and do not create a chafing hazard. 

DGAEPM Modification Process 

2.3.24  Prior to the DND/CAF Airworthiness Program, an internal 1993 audit by the Chief of Review Services identified deficiencies that showed the need for the creation of a more structured airworthiness program.  In response to these concerns, the DND/CAF Airworthiness Program was created, with the original Concept Paper approved on 16 September 1998.

2.3.25  Over the years, the DND/CAF Airworthiness Program has developed into a robust program where airworthiness activities are completed to accepted standards, performed by authorized individuals, accomplished within accredited organizations and done using approved procedures.  The current procedure for reviewing, approving, granting airworthiness clearance and release for modifications, alteration and new alternate parts for aerospace equipment and products is documented in procedure AEPM EMT04.001.  As part of this process, the modification documentation file is staffed for review and approval under cover of the Aircraft Modification Airworthiness Form (AMAF), which serves as the sign-off document for the modification.  The investigation noted that the deficiencies observed in the MPP approval process which in effect short-circuited the modification process, have been well addressed by current technical airworthiness policy and procedures.  

2.3.26  Block 2B of the AMAF, Specialist Airworthiness and Technical Review, provides for review of numerous specialists items such as structural strength and fatigue, electrical power adequacy and electromagnetic compatibility.  However, the AMAF does not specifically require review for impact to electrical wiring or flammable fluid carrying lines.  In carrying out any modification or design change, it is crucial to ensure that flammable lines and/or wiring are properly routed, supported and protected from chafing, abrasion, harsh environments and damage from anticipated hazards.  The investigation concluded that, due to the potential criticality of this design element, review and sign-off of these items, as detailed in CFTO C-12-010-040/TR-010 (Aircraft Flexible Hose Standard Manufacture, Replacement and Inspection) and CFTO C-17-010-002/ME-001 (Aircraft Electrical and Electronic Wiring), should be included in the design modification process.

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2.4  Routing, clamping and chafing – Continuing airworthiness

FSOMS 151598

2.4.1  As previously stated (paras 2.2.11 and 2.2.12), on 24 February 2012 after learning of the accident, an unofficial inspection by a squadron member identified three additional CC130 aircraft at 435 Sqn with chafed auxiliary hydraulic motor power cables (FSOMS 151598).  The chafing occurred where the power cable and the auxiliary hydraulic system pressure line (flexible hose assembly) made contact.  A review of each aircraft’s maintenance history determined that in each instance, the last recorded maintenance action was replacement of the auxiliary hydraulic pump and that subsequently, the current R&O Contractor had performed a Periodic Inspection of the aircraft which includes an inspection of this area.  However, due to the length of time since either the auxiliary hydraulic pump replacement or the Periodic Inspection, it could not be determined if the hydraulic lines and pump wires were installed with insufficient clearance or they had come into contact while in service.  However, the length of time since work had been performed in this area, combined with the visible location of the chafing on these aircraft indicated that routing and clamping issues were routinely not detected and/or corrected.   

2.4.2  This observation was further reinforced when investigators visited the current CC130 R&O contractor to conduct a Flight Safety survey in June 2013.  During this visit, a walk-through of CC130337 undergoing Periodic Inspection revealed that several electrical wires were in direct contact with utility system hydraulic lines, and that these deficiencies had not been identified during the inspection phase of the Periodic Inspection.  These deficiencies were brought to the attention of the contractor and corrected.

Special Inspections (SIs)

2.4.3  As a result of the findings from FSOMS 151598, the CC130 WSM released Special Inspection C-12-130-000/NS-702 (SI NS-702), dated 01 March 2012 to inspect all auxiliary hydraulic lines, wiring and components for serviceability.  Of the 19 aircraft inspected by SI NS-702, 10 aircraft were found unserviceable with 33 hydraulic lines found damaged or chafed and with a maximum of nine observations found on a single aircraft.  In addition, 15 wire bundles were found damaged or incorrectly wrapped.  Also, four instances of physical damage to pump/attachment/fittings were found and two clamps were found missing. 

2.4.4  A check of the maintenance records for 435 Sqn based-aircraft CC130338, showed SI NS-702 was completed on 2 March 2012.  Subsequently, on 7 March 2012, an investigator visited 435 Sqn on a related item and observed an auxiliary hydraulic rigid line (tube assembly hand pump suction (aluminum)) in contact with the tee fitting portion of the auxiliary hydraulic pump inlet line.  Furthermore, examination of the drip pan drain valve showed it to be closed without lockwire, contrary to paragraph 9b of the SI.  The 435 Sqn Squadron Aircraft Maintenance Engineering Officer (SAMEO) was advised and the SI was repeated on all 435 Sqn aircraft on 8 March 2012 to check for compliance with the SI, and to rectify omissions.

2.4.5  In addition, the WSM released an additional SI NS-705 on 28 August 2012 to inspect the auxiliary hydraulic test connection pressurized hydraulic lines for condition and correct configuration.  Of the 19 aircraft inspected, seven were found unserviceable, with six incorrect hose part numbers detected.  In addition, one chafed hose was found and one instance of contact was found between a hose and a wire bundle.

2.4.6  The WSM re-issued SI NS-702 as SI NS-718 on 22 August 2014 to confirm if the risk of chafing had been resolved.  Of the 16 aircraft inspected, four were found unserviceable including six chafed or damaged hydraulic lines, three instances of contact between hose or structure and wire bundle, one loose union and one plug missing lockwire.  Due to the continuing discrepancies being found, the WSM re-issued SI NS-702 a third time as SI NS-729 on 09 March 2015 as a preventive measure to be completed by 30 June 2015, to ensure continued airworthiness of the CC130 fleet until a long term solution could be implemented.  

2.4.7  As another preventive measure the WSM issued a Tech Awareness bulletin, MA-13-0007-TECH that highlighted key sections of CFTO C-17-010-002/ME-001, Part 8 regarding the requirements and acceptable separation methods for routing and clamping of wire bundles in the vicinity of flammable lines.  This bulletin was included in the CC130 IETM and hyperlinked to the applicable paragraphs of the CC130 maintenance CFTOs.

Routing and Clamping as a Continuing Airworthiness Concern

2.4.8  In spite of the high profile of this accident and the potential hazard to airworthiness, issues related to routing, clamping and chafing continued to persist on the CC130 fleet and flight safety reports have continued to be generated (ex FSOMS 152856, 154490, 160690 and 167072).  It is of concern that problems are not being detected at squadron level and during third line R&O maintenance, in spite of numerous scheduled visual and detailed inspections of these areas. 

2.4.9  Routing and clamping has been a previous issue upon which DFS conducted a prevention campaign in the late 1990s and was on the “Top Ten” safety concerns list in that era.  In 1998, the fire on-board Labrador CH11305, which resulted in the loss of the aircraft and six crew members, was likely initiated as a result of chafing on the main fuel line of the #2 engine.  In 1994, Sea King CH12425 crashed, with two crew members killed and two seriously injured, after an on-board fire that was initiated by a leak in a main engine fuel line that was chafed through by a drain line.   

2.4.10  In 1996, FSOMS was modified to include the use of the term “routing and clamping” as a key word for search purposes.  Since 1996, over 1000 occurrences have been identified as being caused due to routing and clamping and/or chafing, many involving wiring and/or flammable fluid carrying lines.  While the FSOMS reports dropped from approximately 100+ per year initially, to approximately 20 to 30 per year by 2005, FSOMS occurrence reports seem to be gradually increasing with 39 reports generated in 2014.  This issue spans across the entire Royal Canadian Air Force (RCAF) and no fleet is immune to this problem.

2.4.11  DFS used this accident to once again raise general awareness of routing, clamping and chafing issues during the 2012-2013 annual flight safety briefing provided across the RCAF and in an article within the widely circulated Flight Comment magazine, Issue 4, 2012. 

2.4.12  The Canadian Forces School of Aerospace Technology and Engineering (CFSATE) offers instruction to Aviation Technicians on the routing and clamping of flexible and rigid tubing.  In addition, CFSATE recently created a training package dealing with the routing and clamping of electrical wiring. This training will soon be delivered to all aircraft technical trades at CFSATE, during the Common Core training portion. The Electrical Wiring Interconnect System (EWIS) training is delivered on stand-alone computers to Common Core students, while ACS Gap training students receive it via DNDLearn.  Using the Defence Wide Area Network, DNDLearn is available to everyone, so this training could theoretically be made available to current technicians and Aeronautical Engineers as well, but there are not any existing plans to deliver EWIS to those groups.

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2.5   WSM Modifications – Post-accident

2.5.1  As a result of the accident and continuing chafing issues highlighted by flight safety reports and the results of SIs NS-702 and NS-718, the WSM undertook a complete rationalization and redesign of modification CF-378.  The WSM first determined that the modification to install test connections was required and then completed a redesign of the modification to address the safety issues identified.   

2.5.2  This new modification leaflet C-12-130-000/CD-154 (CD-154) removes the original CF-378 modification and hydraulic pump motor wiring.  The redesign includes a new routing and clamping configuration for the hydraulic lines associated with the ground test connections, as well as new routing and clamping for the pump motor wiring harness.  Modification CD-154 will use stand-offs and clamps to secure the hydraulic hoses and wiring to nearby structure to eliminate the potential for chafing.  Modification CD-154 passed critical design review on 02 Oct 2014, with a proof fit and prototype installation completed.  Full implementation is scheduled for 2016.

2.5.3  In addition, the WSM authorized the conversion of hydraulic fluid used on all hydraulic systems on the CC130E and CC130H aircraft from MIL-H-5606 to MIL-PRF-87257.  This conversion was implemented via Message DAEPMTH 22108 dated 061430Z Mar 14 and by modification leaflet C-12-130-000/CF-927 dated 2014-07-04.  MIL-PRF-87257 is a fire resistant, synthetic hydrocarbon base hydraulic fluid which specifies a minimum flash point of 160ºC (320ºF).  For electrical arcing events, localized temperatures can exceed 5700ºC so the increase in flash point can be considered insignificant with respect to fire initiation.  The fire resistant designation refers to the ability of the flammable to self-extinguish when the ignition source is removed.  While generally considered as less hazardous than MIL-H-5606, it is not possible to determine if the use of MIL-PRF-87257 would have resulted in a different outcome in this particular accident.

2.5.4  The WSM continues to track the airworthiness risk associated with this occurrence under Record of Airworthiness Risk Management (RARM) CC130-2012-001, Fire in the Aft Upper Fuselage.  The current version 4 of the RARM, dated 02 December 2013, has a risk index of Acceptable Level of Safety (ALOS).

2.6  Operational Response

2.6.1  Concurrent with the V1/rotate call, LM1 emphatically informed the crew of the fire in the cabin.  P3 sensed the urgency of the situation, assessed the runway remaining as adequate and landed straight ahead.  Although most simulator training scenarios dictate continuing the take-off after a V1/rotate call, P3 had no doubt that the correct course of action was to land immediately. The time from LM1 announcing the fire to the time that CFR crews extinguished the fire was just under four minutes.  At some point during this period, the elevator and rudder control cables failed.  Had the crew continued the take-off with a planned emergency return, it is likely that these control cables would have failed at some point during the emergency return, resulting in the loss of aircraft control.  The investigation concluded that the crew’s reaction to this non-standard critical emergency was not only correct, but likely the only course of action that prevented the loss of both aircraft and crew.

2.6.2  Once stopped, the flight deck crew detected the heat and smoke from the fire entering the flight deck.  Aware that cabin evacuation activities were already underway to escape the expanding fire, the Ground Evacuation checklist was not called for.  P1 directed that only critical items in the checklist such as condition levers, fire handles and battery bus tie switches be actioned in order to expedite the evacuation.  All crewmembers egressed via the crew door and distanced themselves from the aircraft.  The crew’s response was not strictly in accordance with  the Ground Evacuation checklist, however, their actions were consistent with  the emergency actions fundamental principles as stated in C-12-130-000/MB-001 Part 3, Section 1 and entirely appropriate given the urgency of the situation.

2.7  Collateral Observation: Dual Layer Principle

2.7.1  Current Air Division Orders regarding use of dual layer clothing is found in the RCAF Flight Operations Manual (FOM), Chapter 4, Section 2.2 which states that the intent is for personnel to always wear an outer fire resistant layer over top of an inner insulative layer.  The outer layer provides flame protection and spreads out the heat, whereas the inner layer, as well as air trapped between the two layers, insulates the body to the level required to minimize injury. 

2.7.2  In this accident, the dual layer concept was not adhered to as dual layer clothing below the waist was not worn by any of the crew.  At the time of the fire, the outside air temperature at NASKW was 21ºC and LM1 was wearing a CADPAT intermediate weight jacket as an outer layer over his CF flight suit, indicating that heat stress was not of immediate concern. 

2.7.3  RARM ALSE-2011-003, 22 March 2011, was raised to document the risk of flying operations without dual layer protection.  The airworthiness risk index was assessed as B4-ALOS with a survivability risk index of B3-Medium.  The Operational Airworthiness Authority (OAA) accepted the risk of Unit COs relaxing the requirement for dual layer protection and directed that 1 Canadian Air Div Order, Vol 2, 2-007 Safety Requirements clearly state who has the authority to waive the dual layer requirement. 

2.7.4  Order 2-007 was subsequently relocated to the RCAF FOM Chapter 4, Paragraph 4.2.2.1 which now states: “WComds/Unit COs/Commandants are authorized to waive the dual layer clothing requirement, when climatic conditions or mission profiles could unduly degrade aircrew effectiveness due to heat stress.  Unit flying orders shall include direction to this effect.”  However, a review of current 435 Sqn Orders revealed no specific direction with respect to wearing dual layer protection.  Unit COs are required to provide clear direction as to both the circumstances and the procedure they will use to waive the dual layer requirement. 

2.7.5  The non-use of dual layer protection has been observed in a number of accidents investigated by DFS across the RCAF, potentially indicating a more systemic issue.  A review of all Wing and Unit flying orders should be conducted to ensure that direction concerning dual layer protection, as articulated in the RCAF FOM, has been implemented at all Wings and Units as intended.  The results of this review should be documented in the next annual review of RARM ALSE-2011-003, scheduled for October 2016.

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2.8  Collateral Observation: Technicians as crew members Policy

2.8.1  To be considered as crew, National Defence Flying Orders specify a number of requirements that need to be satisfied including undergoing or completing qualifying courses, successful completion of aeromedical training, the wearing of appropriate crew clothing and life-support equipment and participating in crew briefings.  By contrast, passengers need to be briefed on emergency procedures and the location and operation of life support equipment, as well as being appropriately supervised while on-board. 

2.8.2  The maintenance technicians were listed as crew members on Form CF/K1017, Flight Authorization and Record of Flight.  Although the technicians were listed as crew, they had not received CC130 aircrew specific training and they had no specific in-flight duties; they were on-board for mission expediency in order to refuel and replenish the LOX system while the aircraft was on the ground at NASKW.

2.8.3  For the accident flight, the number and type of aircrew were sufficient to meet minimum crew requirements for AAR operations.  However, had the technicians been listed as passengers, a number of restrictions would have been applicable to the AAR mission including not conducting receiver conversion training and being limited to single hose operations.

2.8.4  Prior to the accident flight, no passenger briefing was provided to the technicians as they were considered as crew.   However, MT2 did not attend the on-board crew brief, which included a review of the evacuation plan, as he was outside the aircraft standing by to remove the aircraft power cart.  Also, the technicians were wearing CADPAT clothing with blue t-shirts, which was their daily dress for maintenance activities.  CADPAT is not flame resistant and is not approved for aircrew wear in flight. [9]  While the technicians were identified as crew members, they were de facto treated as passengers in that they did not get the requisite crew training and briefings, nor did they wear the appropriate crew flying clothing.

2.8.5  Neither National Defence Flying Orders nor the FOM specifically detail the crew requirements for technicians when carried as crew members.  This is a policy gap that should be filled by explicitly detailing the requirements for the carriage of technicians as crew members, including training, clothing, life support and crew briefing requirements, to ensure that technicians as crew members can function appropriately in routine and emergency situations. 

2.8.6  In addition, it was noted that the FOM Annex 2.2.1.1.B does not include specific direction for the carriage of technicians as crew members on board CC-130H flights/missions.  Specific direction should be provided in the FOM for the carriage of technicians as crew on the CC-130H, similar to direction in place for other transport fleets.

2.8.7  As an immediate preventive measure, the CC130 Loadmaster Duties/Amplified Checklist found in the Standard Manoeuvre Manual (SMM) SMM-60-130-0917 was revised to state: “non-qualified CC130 crewmembers shall be briefed as a passenger”.  In addition, the Ground Evacuation and Ditching Briefing in the Loadmaster checklist SMM-60-130-0912 was amended to include the use of the passenger alarm bell as a ground evacuation signal as identified in C-12-130-000/MB-001, PART 3, Section 1.

2.9  Collateral Observation: Closed Drain Valve

2.9.1  Modification CF-694 requires the reservoir drip pan drain valve for the auxiliary hydraulic system to be lockwired in the open position.  The drain valve on the accident aircraft was retrieved and examined at QETE.  The valve was found spring loaded in the closed position but, with the knob missing, it was not possible to determine the valve’s position at the time of the accident.  The lockwire hole was present in the valve body as per modification CF-694; however, there was no evidence to indicate it was lockwired.

2.9.2  Shortly after completion of SI NS-702, investigators found the reservoir drip pan drain valve on CC130338 closed, in contravention of both CF-694 and NS-702.  During the course of the investigation, closed reservoir drip pan drain valves were observed on other CC130 aircraft (see also FSOMS 153199 and FSOMS 153509).  Squadron personnel indicated that even though the modifications and inspections had been signed off, the actual practice was to close the drain valve as the opening to the external fuselage created a constant pressurization leak and an annoying whistling noise during flight. 

2.9.3  It was noted that modification CF-694 received initial resistance from field units during implementation, with a UCR submitted by CFB Edmonton/ BAMEO/ AMCRO D0127/3002 dated 29 January 1993 requesting removal of CF-694 for aircraft cleanliness reasons.  This UCR was rejected with WSM comments that “leakage past the nine port valve can result in excessive amounts of hydraulic fluid accumulating in the drip pan.” 

2.9.4  The investigation found that in spite of instructions to open the valve, including a modification to permanently lockwire the valve open, undetermined unit personnel routinely circumvented modification CF-694 by removing the lockwire and closing the valve.  As a result of these observations, Unsatisfactory Condition Report (UCR) 2521/2012/0004 dated 20 March 2012 was raised to close the drain valve for environmental and in-flight pressurization reasons.  Modification CD-154 addresses both the new UCR and the concern of non-compliance with modification CF-694 by blanking off the overboard drain and installing an overflow reservoir with in-board drain capabilities.

2.10  Collateral Observation: Lifting of Operational Pause

2.10.1  On 21 Feb 2012, the day of the accident, the Commander (Comd) 1 Canadian Air Division (1 CAD) imposed an operational pause on the CC130E/H/J fleets in which the fleet was restricted to flying essential SAR/Force Employment missions only. [10]  

2.10.2  Shortly after the accident, DFS provided a photograph to the WSM of an external view of the aircraft showing the hole in the top of the fuselage.  Based on this photograph, a CC130 Technical Services Rep speculated the cause of the accident, “with a high level of confidence”, to be “that an oxygen breach occurred in the area of the hole in the upper fuselage, caused an explosion through some means (static discharge or fluid residue contact) and the resulting high intensity fire quickly melted through the hydraulic lines running aft.  The burning hydraulic fluid would then have been sprayed over the auxiliary pump area causing secondary fire damage.” 

2.10.3  On 22 Feb, an Airworthiness Risk Alert (ARA) was raised by the WSM which assessed the risk as A3 high.  The hazard cause in the ARA stated that “an oxygen breach occurred in the oxygen line near FS737, resulting in a high intensity fire” and the ARA situation summary essentially repeated the speculation of the CC130 Technical Services Rep. This was confirmed by the WSM through an informal survey of a CC130J aircraft. To mitigate the perceived risk, a before next flight SI, C-12-120-000/NS-701 (SI NS-701) was issued to inspect the cargo compartment rigid oxygen tubing for damage.  Upon completion of the SI, the risk was reduced to A4 medium.  However, while the oxygen breach was deemed to be the most probable cause, the ARA stated that the level of confidence was “Low” as the investigation was in the preliminary stage. 

2.10.4  The WSM also determined that the newer CC130J aircraft were not at risk due to configuration differences in that the oxygen and hydraulic lines, as well as the lack of an internal fuselage tank vent line, in the vicinity of the oxygen distribution system. In addition, the new state of the recently purchased CC130J had less potential for wear, damage or chafing issues.  These observations were confirmed by an informal survey of a single CC130J aircraft.

2.10.5  On 22 Feb, the Technical Airworthiness Authority (TAA) and OAA approved the ARA and the Deputy Commander Force Generation  (DComd FG) accepted the risk as the Acting Comd 1 CAD.  In addition, on 22 Feb, the Acting Comd 1 CAD rescinded the operational pause for the CC130J fleet and directed that normal operations could resume on any CC130E/H aircraft that had been inspected in accordance with the SI NS-701.  The message was distributed to all Wings that operated CC130 aircraft.  The TAA, WSM and AIA were not aware that the operational pause had been rescinded.

2.10.6  On 24 Feb, a 435 Sqn member, unsatisfied with the explanation for rescinding the operational pause, took it upon himself to conduct an unofficial inspection of the aircraft at 435 Sqn, resulted in the finding that hydraulic lines associated with the ground test connection modification were chafing the auxiliary hydraulic pump motor power cables on three additional aircraft (FSOMS 151598, also see Figures 13 and 14).  With evidence also mounting from the investigation that the cause of the fire was related to the auxiliary hydraulic system and not the oxygen system, the Comd 1 CAD reinstated the operational pause for the CC130E/H fleets on 27 Feb, restricting flights to essential SAR/Force Employment missions only.  The operational pause on the CC130J was not reinstated as the auxiliary hydraulic system ground test modification was not embodied on the CC130J fleet.

2.10.7 On 29 Feb, the AIA advised the Chief of the Air Force of an additional preventive measure that Director General Aerospace Equipment Program Management (DGAEPM) to inspect for auxiliary hydraulic pump wiring, specifically contact between hydraulic flex lines and wiring harnesses.  The ARA was revised on 01 March to correctly identify the hazard as the wiring harness of the auxiliary pump chafing on the braided hydraulic flexible hose, with the breach in the oxygen line and the fuselage ceiling recognized as secondary fire damage. The risk index was reset from A4 medium to A3 high.  Two additional SIs were issued to inspect all hydraulic lines, wiring and components on all CC130 E/H aircraft (SI NS-702), as well as to inspect the cargo compartment fuel vent tubing on the H(T)90 tanker aircraft (SI NS-703).  Upon completion of SI NS-702, the risk index was revised to A5 – Acceptable level of safety (ALOS).   On 03 March, the Comd 1 CAD cancelled the operational pause on the CC130E/H fleets and normal operations resumed.

2.10.8  During the initial phase of an accident investigation, speculation as to cause factors can inadvertently undermine the airworthiness of the fleet, especially if decisions are made as a result of inaccurate information.  The initial ARA clearly identified that the confidence in the assessment was LOW, yet downgraded the risk level from HIGH to MEDIUM based on completion of the SI NS-701.  In turn, the Comd 1 CAD allowed the fleet to resume operations after completion of SI NS-701, based on the revised risk level of the ARA.

2.10.9  The WSM, TAA and the AIA were not aware that the operational pause had been lifted.  The distribution list for the operational pause and reinstatement messages was to flying units and does not include the WSM, TAA or the AIA.  This lack of communication from the Comd 1CAD back to the WSM, TAA and AIA allowed the perception of reduced risk to go unchallenged, with the result that the fleet was exposed to elevated risk for a period of five days, post-accident until the hazardous condition was discovered on three additional aircraft and operational pause was reinstated.  This issue was discussed at the Fall 2013 and Spring 2014 Airworthiness Review Boards (ARB) in which it was agreed that the AIA and DTAES should be included on the 1 CAD Combined Aerospace Operating Center (CAOC) distribution list for the issuance of operational pause instructions.  However, at the Fall 2014 Executive ARB, the Senior Staff Officer - Operational Airworthiness (SSO OA) indicated that there was no formal process for ensuring the AIA was included in any discussions related to imposing or removing an operational pause. 

2.10.10  The SSO OA committed to informing the AIA concerning any operational pause in future in the absence of a formal procedure, but there was no commitment to creating such a process. The lack of a formal methodology to keep the AIA and TAA informed regarding operational pauses and their status puts RCAF personnel and fleets at risk due to the possibility of decisions being made without complete information.  Although there is now a commitment to informally pass this information to the AIA, the proposal is personnel dependant and thus unreliable in a dynamic RCAF environment.

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3   CONCLUSIONS

3.1  Findings

3.1.1  The source of fuel for the fire was hydraulic fluid that sprayed from a breach in a high pressure hydraulic flex hose (P/N AE 2460010-H-0282) in the auxiliary hydraulic system. (2.2.10)

3.1.2  The hydraulic flex hose had a stainless steel outer braid which came into contact with the auxiliary hydraulic pump motor power supply wiring and chafed the wiring insulation to the point where the underlying power supply wires were exposed to the stainless steel braiding. (2.2.10)

3.1.3  The breach in the high pressure hydraulic flex hose resulted from an electrical arcing event between the auxiliary hydraulic pump motor power supply Phase B wire and the hydraulic line.  (2.2.10)

3.1.4  The ignition source for the fire was electrical arcing between the auxiliary hydraulic pump motor power supply Phase B wire and the hydraulic flex hose.  (2.2.10)

3.1.5  The hydraulic flex hose was part of modification CF-378 to install ground test connections on the auxiliary hydraulic system and was the line connecting the pressurized test connection with the auxiliary hydraulic system. (2.2.2)

3.1.6  The original modification CF-378, dated 08 October 1976 was re-issued 20 September 1989 “to correct text” of the original modification leaflet.  The changes included minor amendments to part numbers, conversion to bilingual format, and a change to drawing views. (1.18.3, 1.18.4)

3.1.7  The R&O contractor was tasked to install modification CF-378 on aircraft CC130338 through CC130344 inclusive, but was unable to install the modification IAW the re-issued modification leaflet. (1.18.5, 1.18.6)

3.1.8  The R&O Contractor developed an alternate installation and submitted a MPP to the LCMM to be approved as a standard repair (2.3.2, 2.3.3)

3.1.9  The MPP was submitted to the LCMM on the Friday before a long weekend with instructions to “treat as urgent”, as flight test was scheduled for the following week. (2.3.3)

3.1.10  A DTA staff member concurred with the MPP the next working day after the long weekend and the LCMM authorized the MPP two days later.  No evidence was found to document the extent of the review of the MPP that was carried out by the LCMM or by the DTA staff member.  (2.3.4)

3.1.11  The R&O contractor installed modification CF-378 on aircraft CC130338 through CC130342 in accordance with the MPP.  (1.18.6, 2.3.5)

3.1.12  The MPP did not locate the test connection support bracket at the correct location; it was installed 5 inches in-board of the correct location. (2.3.7)

3.1.13  The incorrect bracket location resulted in numerous configuration changes to modification CF-378.  (2.3.8)

3.1.14  If the test connection bracket had been located correctly, modification CF-378 could have been installed IAW the modification leaflet and an MPP would not have been required. (2.3.9)

3.1.15  The incorrect location of the support bracket was likely due to changes to the re-issued modification leaflet CF-378 that omitted location details for mounting the test connection bracket, combined with an ambiguous drawing of the mounting location. (2.3.12)

3.1.16  In the MPP, the length of the pressurized hydraulic flex hose leading from the test connection was lengthened by 10 inches from 28.25 inches to 38.25 inches.  The longer hydraulic hose was listed as an alternate part in the parts manual but there was no indication that the longer hose should have been applicable only to H(T)90 and H-30 model aircraft which had embodied modification CF-378 IAW the MPP (2.3.8, 2.3.14)

3.1.17  The shorter 28.25 inch hydraulic flex hose was found installed on the accident aircraft as well as all other aircraft in which modification CF-378 was embodied using the MPP.  (2.2.2, 2.3.15)

3.1.18  The lack of appropriate documentation detailing the longer flex hose as being applicable to MPP installations resulted in the shorter flex hose being installed on all aircraft which although listed as the primary part, was not intended to be applicable to these installations.  (2.3.15)

3.1.19  The shorter 28.25 inch hydraulic hose resulted in a routing closer to the back edge of the pump motor tray and to the hydraulic pump motor wiring. (2.3.8, 2.3.15)

3.1.20  Neither modification CF-378 nor the MPP contain specific provisions for routing or clamping of the hydraulic hoses, or for separation of the hydraulic hoses from the pump motor wiring. In practice, incorrect attempts to prevent chafing were observed including the use of electrical tape and/or plastic sheathing being commonly used to wrap the pump motor wire.  (2.3.20, 2.3.21)

3.1.21  The pressurized hydraulic flex hose leading from the test connection, introduced by modification CF-378, was longer than 24 inches, but was not clamped IAW CFTO C-12-010-040/TR-010. (2.3.20)

3.1.22  Neither the hydraulic flex hose nor the wire bundle was adequately clamped to ensure separation of the wire bundle from the flammable line, in contravention of CFTO C-17-010-002/ME-001, Aircraft Electrical Wiring and Electronic Wiring, Part 8, Chapter 1.  (2.3.23)

3.1.23  The urgent MPP short-circuited the modification process and resulted in an insufficient review of the design changes proposed.  (2.3.13)

3.1.24  The current DGAEPM modification process does not include a specific sign-off review of routing and clamping for electrical wiring or for lines carrying flammable fluid to prevent chafing, abrasion, or other damage through various mechanical or chemical mechanisms or harsh environments as detailed in CFTOs C-12-010-040/TR-010 (Aircraft Flexible Hose Standard Manufacture, Replacement and Inspection) and C-17-010-002/ME-001 (Aircraft Electrical and Electronic Wiring). (2.3.26)

3.1.25  There has been a history of chafing of both high pressure hydraulic flex hoses associated with modifications CF-245 and CF-378 on the pump motor tray and support structure. (2.3.18, 2.3.19)

3.1.26  A review of 435 Sqn aircraft, three days after the accident, found that the hazardous condition of the hydraulic flex hose coming into contact and chafing on the auxiliary pump motor power supply wiring was present on three additional CC130 aircraft. (2.2.11)

3.1.27  Routing, clamping and chafing issues involving the auxiliary hydraulic system are not being detected and/or corrected by first line or R&O technicians. (2.4.1, 2.4.2, 2.4.6, 2.4.8)

3.1.28  Routing, clamping and chafing continue to be hazards to continuing airworthiness throughout the RCAF.  (2.4.10)

3.1.29  The crew’s reaction to this non-standard critical emergency was correct and likely the only course of action that prevented the loss of the aircraft and crew. (2.6.1)

Collateral Findings

3.1.30  The deployed computer contained an out-of-date copy of the IETM. (1.18.11)

3.1.31  Aircrew were not wearing dual layer protection from the waist down. (2.7.2)

3.1.32  LM1 was wearing his CADPAT intermediate weight jacket as an outer layer over his flight suit at the time of the occurrence (2.7.2)

3.1.33  No direction currently exists with 435 Sqn Orders as to the circumstances and the procedure for waiving the dual layer requirement.  (2.7.4) 

3.1.34  The maintenance technicians were listed as crew members for the mission.  However, they had no in-flight duties and were on-board for mission expediency in order to provide maintenance services while the aircraft was on the ground during a scheduled stop. (2.8.2)

3.1.35  While the maintenance technicians were identified as crew members, they were de facto treated as passengers in that they did not get the requisite training and briefing, nor did they wear the appropriate crew flying clothing.  (2.8.4)

3.1.36  Neither National Defence Flying Orders nor the FOM specifically details the training, clothing, life support equipment and crew briefing requirements for technicians when carried as crew members. (1.18.22, 2.8.5, 2.8.6)

3.1.37  The FOM Annex 2.2.1.1.B does not specify the carriage of technicians as crew members for flights/missions on the CC-130H Hercules aircraft.  (1.18.20, 2.8.6)

3.1.38  A number of CC130 aircraft were found to have the auxiliary system drain valve closed, in contravention of modification CF-694 and SI NS-702 which required the drain valve to be lockwired open. (2.9.2, 2.9.4)

3.1.39  The operational pause was lifted prematurely, based on inaccurate speculation as to the cause of the fire/accident. (2.10.8)

3.1.40  There was no communication from the OAA back to the TAA and AIA regarding the lifting of the operational pause.  (2.10.9)

3.2  Cause Factors

General

3.2.1  The fire was ignited due to an electrical arcing event that occurred between the auxiliary hydraulic system pump motor power supply wire harness and a pressurized auxiliary hydraulic stainless steel braided flex hose installed as part of modification CF-378.  The stainless steel braided flex hose chafed through the electrical insulation of the wire and the subsequent electrical arcing from the wire resulted in a 2mm hole in the flex hose, leak of high pressure hydraulic fluid and ignition of the hydraulic fluid. (2.2.10)

Design Approval Cause Factors

3.2.2  The CF-378 modification leaflet did not specify sufficient routing and clamping arrangements to maintain separation of the pressurized hydraulic lines from support structure and the hydraulic pump motor wire and the re-issued CF-378 modification leaflet was ambiguous as to the correct location of the test connection support bracket. (2.3.12, 2.3.20)

3.2.3  The approval process for the MPP was deficient in that it did not detect the improper location of the ground test connection bracket, did not adequately consider the effect of the redesign on routing and clamping, did not treat the revised configuration as a new modification, and did not specify the application of the MPP installed alternate parts in the amended parts list. (2.3.13, 2.3.14, 2.3.15)

3.2.4  The modification approval process did not contain specific provisions to consider impacts of routing and clamping for wiring hoses IAW CFTOs C-17-010-002/ME-001, Aircraft Electrical and Electronic Wiring and for flexible hoses IAW CFTO C-12-010-040/TR-010, Part 3 Aircraft Flexible Hose Standard Manufacture, Replacement and Inspection. (2.3.23, 2.3.26)

Maintenance Cause Factors

3.2.5  Maintenance personnel and supervisors at all levels did not detect and/or correct deficiencies related to routing and clamping of lines and wires for modification CF-378 and the associated MPP, either during installation and/or subsequent inspections. (2.2.12, 2.4.1, 2.4.8)

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4  PREVENTIVE MEASURES

4.1  Preventive Measures Taken

4.1.1  The DND/CAF Airworthiness Program has established effective policy and procedures for approval of modifications and standard repairs that have addressed the deficiencies in the MPP approval process which were in place at the time. (3.2.3)

4.1.2  CC130 WSM issued a series of SIs of E and H model CC130 aircraft to be conducted on the auxiliary hydraulic system components, checking for evidence of chafing against structure or components, proper routing, clamping, and wiring to ensure adequate clearance exists between items.  (3.2.5)

4.1.3  CC130 WSM redesigned the auxiliary hydraulic test connections.  Modification CD-154 is a complete redesign that removes modification CF-378 and addresses routing and clamping issues to prevent chafing.  Modification CD-154 also addresses the collateral observation of non-compliance with modification CF-694 (lockwiring open the auxiliary hydraulic drain valve).  (3.1.38, 3.2.1, 3.2.2)

4.1.4  DFS raised awareness of routing, clamping and chafing through the annual FS brief and the Flight Comment magazine. (3.2.5)

4.1.5  435 Sqn SAMEO amended the deployable CFTO library work procedure D/AMCRO 4.5-7 to ensure that the latest version of the IETM is available for use on deployment. (3.1.30)

4.1.6  CC130 WSM issued instructions to convert all CC130 on CC130E and CC130H aircraft hydraulic systems to use MIL-PRF-87257, a fire-resistant synthetic hydraulic fluid with a higher flashpoint.  Modification CF-927 is complete and full conversion will be achieved by Fall 2016 (2.5.3)

4.1.7  Comd 1 CAD / OC TRSET amended SMM-60-130-0917 (CC130 Loadmaster Duties/Amplified Checklist) to include direction to brief aircraft evacuation procedures to non-qualified crew members as if they were passengers. (3.1.35)

4.1.8  Comd 1 CAD / OC TRSET amended SMM-60-130-0912 (LM Checklist) to reflect the use of the passenger alarm bell as a ground evacuation signal as identified in C-12-130-000/MB-001, PART 3, Section 1, Paragraph 6. (2.8.7)

4.1.9  Comd 2 CAD / CFSATE created a training package dealing with routing and clamping of electrical wiring.  (3.2.5)

4.2  Preventive Measures Recommended

4.2.1  CC130 WSM to complete the embodiment of modification CD-154 on all flying aircraft.  This is currently planned for completion in 2016.  (3.1.38, 3.2.1, 3.2.2)

4.2.2  CC130 WSM to conduct an airworthiness review of all contractor MPP-implemented modifications on all CC130 E/H model aircraft that could potentially affect the safety of flight, in order to ensure airworthiness and configuration control issues have been properly addressed and documented. For any discrepancies identified throughout this review process, an airworthiness impact assessment shall be conducted followed by adequate corrective actions and measures.   (3.2.3)

4.2.3  DGAEPM /TAA to amend the EMT04.001 modification procedure to include specialist/specific review of wiring and hydraulic lines to ensure proper routing, support and protection from chafing, abrasion, harsh environments and damage from anticipated hazards.  (3.2.4)

4.2.4  Comd 2 CAD to direct CFSATE to incorporate this accident into aerospace engineering and technician training to emphasize the importance of detecting improper wire and hydraulic line clamping, to identify ambiguous engineering instructions and to heighten awareness for the consequences of inter-component chafing. (3.2.5)

4.3  Other Safety Measures Recommended

4.3.1  CO 435 Sqn to amend Unit Orders to comply with RCAF FOM requirements to provide clear direction for the waiving of the dual layer principle. (3.1.31, 3.1.33)

4.3.2  Comd 1 CAD/OAA to review Wing and Unit implementation of RCAF FOM on dual layer protection, with results to be documented in the next annual review of RARM ALSE-2011-003, Flying Operations without Dual-Layer Fire Protection. (3.1.31, 3.1.33)

4.3.3  Comd 1 CAD to amend National Defence Flying Orders and/or the FOM to explicitly define the requirements for the carriage of technicians as crew members, including the necessary training, clothing, life support equipment and crew briefing requirements, to ensure that technicians flying as crew members can function appropriately in routine and emergency situations. (3.1.36)

4.3.4  Comd 1CAD to provide direction in Annex 2.2.1.1.B of the FOM for the carriage of technicians as crew members for missions on-board CC-130H aircraft.  (3.1.37)

4.3.5  Comd 1 CAD/OAA to implement a formal means of notifying the AIA and TAA of operational pauses and their status.  (3.1.40)

4.4  DFS Remarks

4.4.1  Aircraft fires can be particularly hazardous and survival may be dependent on the ability to rapidly egress from a burning aircraft.  The survival of all six crew members and 15 passengers, following an in-flight explosion and fire on CH147202 in Afghanistan, was due in no small measure to the ability to land and egress from the aircraft within 30 seconds of the initial explosion.  Similarly in this case, the quick decision of the crew to land immediately almost certainly prevented a catastrophic accident with loss of life.   Definitive procedures available to cover all emergency situations do not exist, and for this reason checklists, CFTO’s and other publications clearly stipulate that above all else, good judgement and professionalism must prevail. Standard training protocol dictates that multi engine aircraft continue the take-off following a V1/rotate call. However, in this case the decision to abort was a textbook example of exerting superior judgement during an exceptional circumstance.   

4.4.2  In retrospect, the physical cause of the fire was evident.  However, what is not evident is why the hazardous condition was not detected earlier.  There were ample opportunities to detect this hazardous condition on any affected aircraft during any scheduled inspection.  Complacency likely came into play in that the area was looked at many times, without actually seeing, understanding and/or correcting the problem. The short term solution to counter these human factors is through proper technical training, but the long term solution that will pay the greatest dividends is to train the minds of our technicians to expect to find problems every time they do an inspection. 

// Original Signed By //

S.Charpentier
Colonel
Director of Flight Safety

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Annex A – Crew Station Diagram 

Annex B - Fuselage Station Chart

Annex C - Abbreviations

ABBREVIATION - MEANING

1 CAD - 1 Canadian Air Division

2 CAD - 2 Canadian Air Division

°C - degrees Celsius

°F - degrees Fahrenheit

AAR - Air to Air Refuelling

AC - alternating current

AC - Aircraft Captain

ACSO - Aircraft Combat Systems Officer

AF - Air Frame

AFMES - Armed Forces Medical Examiner System

AIA - Airworthiness Investigative Authority

ALOS - Acceptable Level of Safety

ALSE - Aircraft Life Support Equipment

AMAF - Aircraft Modification Airworthiness Form

ARA - Airworthiness Risk Alert

ARB - Airworthiness Review Board

ATC - Air Traffic Control

CADPAT - Canadian Disruptive Pattern

CAF - Canadian Armed Forces

CAOC - Combined Aerospace Operating Center

CB - Circuit Breaker

Cdn - Canadian

CF - Canadian Forces

CFR - Crash Fire Rescue

CFTO - Canadian Forces Technical Order

CFSATE - Canadian Forces School of Aerospace Technology and Engineering

CO - Commanding Officer

Comd - Commander

CT - Crash Truck

CVR - Cockpit Voice Recorder

DC - Direct Current

DComd FG - Deputy Commander Force Generation

DFS - Director of Flight Safety

DGAEPM - Director General Aerospace Engineering Program Management

DND - Department of National Defence

DTA - Directorate of Technical Airworthiness

DTAES - Directorate of Technical Airworthiness and Engineering Support

EWIS - Electrical Wiring Interconnect System

FDR - Flight Data Recorder

FE - Flight Engineer

FO - First Officer

FOM - Flight Operations Manual

FRPC - Flight Recorder Playback Center

FS - Fuselage Station

FSIR - Flight Safety Investigative Report

FSOMS - Flight Safety Occurrence Management System

ft - feet

hrs - hours

IAW - in accordance with

IETM - Interactive Electronic Technical Manual

lbs - pounds

LCMM - Life Cycle Material Manager

LH - Left Hand

LM - Load Master

LMS - Load Monitoring System

LOX - Liquid Oxygen

METAR - Meteorological Aviation Report

MND - Minister of National Defence

MT - Maintenance Technician

MPP - Maintenance Production Permit

NASKW - Naval Air Station Key West

NRC - National Research Council

OAA - Operational Airworthiness Authority

OBB - On Board Brief

P1 - Aircraft Captain

P2 - Level Three First Officer Acting as Aircraft Captain

P3 - Level Two First Officer

PAR - Precision Approach Radar

P/ N - Part Number

psi - pounds per square inch

QETE - Quality Engineering Test Establishment

R&O - Repair and Overhaul

RARM - Record of Airworthiness Risk Management

RCAF - Royal Canadian Air Force

RH - Right Hand

SAMEO - Squadron Aircraft Maintenance Engineering Officer

SAR - Search and Rescue

SI - Special Inspection

SMM - Standard Manoeuvre Manual

SSO OA - Senior Staff Officer - Operational Airworthiness

Sqn - Squadron

SSFDR - Solid State Flight Data Recorder

T&R - Transport and Rescue

TAA - Technical Airworthiness Authority

UCR - Unsatisfactory Condition Report

WComd - Wing Commander

WOW - Weight on Wheels

WSM - Weapons System Manager

Annex D - List of Tables and Figures

List of Tables

Table 1.  Injuries to Personnel

Table 2.  Airframe Hours Table

List of Figures

Figure 1.  Aircraft Exterior – Damage to Fuselage Ceiling Area near LH Side Para Door 

Figure 2.  Aircraft Interior – LH Side, Aft of FS 737:  Main Components of the Auxiliary Hydraulic System

Figure 3.  Fire Damage Aircraft Interior - LH Side, Aft of Para Door:  Auxiliary Hydraulic System Area

Figure 4.  Fire Damage Aircraft Interior – Ceiling LH Side, Aft of FS 737:

Figure 5.  Fire Damage Aircraft Interior – Looking Aft of FS 737:

Figure 6.  CFR Response.

Figure 7.  CF-378 Auxiliary Hydraulic System Ground Test Connections (Aircraft CC130335)

Figure 8.  View of Flexible Hydraulic Hose Assembly & Power Cable (Aircraft CC130342).

Figure 9.  Flexible Hydraulic Hose Assembly and Power Cable below Cannon Plug 

Figure 10.  Close-up of Power Cable and Flexible Hydraulic Hose Assembly in Contact 

Figure 11.  Flexible Hydraulic Hose Assembly after Removal (length:  28.25 inches)

Figure 12.  Close-up of Location of Breach in Flexible Hydraulic Hose Assembly Line.

Figure 13.  CC130341 (24 February 2012):  Chafing between Hydraulic Pump Motor Power Cable and Flexible Hydraulic Hose Assembly.

Figure 14.  CC130341 (24 February 2012):   Close-up of Chafing between Hydraulic Pump Motor Power Cable and Flexible Hydraulic Hose Assembly.

Figure 15. Comparison of CF-378 installations:  Left - Installed using original CF-378 modification leaflet (CC130335);  and Right - Installed using MPP (CC130344)

Figure 16. Comparison of CF-378, Figure 2 Bracket Installation – Original CF-378 showing bracket mounting locations.

Figure 17. Comparison of CF-378, Figure 2 Bracket Installation – Re-issued CF-378 

Figure 18.  Comparison of CF-378, Figure 6 Bracket Installation – Original Photograph (left) and Modification Leaflet Drawing (right)

Figure 19.  CC130334 – Chafing in tray and shelf support bracket related to FSOMS 123703 – Photos taken  04 May 2012 (left) and 29 June 2012 (right)

Figure 20. Example of “secondary alternative clamping” to provide positive separation between auxiliary pump power wire and flexible hydraulic pressure line (CC130335, 8 Wing Trenton, 26 April 2012)

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Notes

[1] Pilot training levels for CC130 First Officers (FO) are defined in terms of levels, progressing from Level I through to Level III prior to becoming an Aircraft Captain (AC).  A Level III FO may be scheduled to fly as Acting/AC on operational or training missions with an AC authorized to carry out Flight Monitors.

[2] Time:  all times in the report are local time unless otherwise indicated.

[3] “Knocking down” the fire refers to reducing the intensity of the fire to the point where the firefighters could enter the fuselage to extinguish it.

[4] All times are from records available just before the flight and include time of last flight

[5] Flash Point:  The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air.

[6] 435 Sqn Orders:  Section 1.3.2, paragraph 4.

[7] Bowen and Shirvill (1994). Combustion hazards posed by the pressurized atomization of high-flashpoint liquids.

[8] Eaton Corporation Aerospace Brochure TF300-1 – Electrical Distribution and Controls, Circuit Breakers Military/Aerospace, dated December 2003.

[9] 1 Cdn Air Div message: ALSE 1201 dated 201529Z Aug 12

[10] Message AOC025 2201444Z Feb 12

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