CT156105 Harvard II - Epilogue

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Report / January 27, 2017 / Project number: CT156105 - A Category

Location: 13 nautical miles (NM) southwest of CYMJ
Date: 27 January 2017
Status: Investigation Complete

Epilogue - PDF version, 139Kb


A CT156 Harvard II was operating out of 15 Wing Moose Jaw SK with a two-pilot crew from 2 Canadian Forces Flying Training School. The crew comprised a Qualified Flying Instructor, who was monitoring from the rear seat, and a student pilot in the front seat, who was the pilot flying. The mission was an instructional flight to practice clearhood sequences, including basic aerobatics.

During the pull up into an aerobatic sequence, the instructor was not satisfied with the manoeuvre’s progress and instructed the student pilot to recover, with the expectation the student would do so via a nose-high unusual attitude recovery. The student pilot did not carry out the expected recovery but believed the aircraft had departed controlled flight and carried out the “Inadvertent Departure from Controlled Flight” procedure. The instructor took control of the aircraft and attempted to carry out an unusual attitude recovery, but believed the aircraft was not responding to control inputs and re-initiated the inadvertent departure from controlled flight procedure. During the subsequent recovery attempt the g-forces decreased, which resulted in a weightless condition in which the engine lubrication system could not supply proper lubricating oil to the engine and reduction gearbox.

Engine performance degraded after the aircraft was recovered. The instructor increased power in an attempt to get on a glide profile for a return to base. The attempt was unsuccessful, and the engine performance continued to degrade, leading the crew to carry out a controlled ejection. Both crew members sustained minor injuries during the ejection; however, the student pilot sustained additional injuries during the parachute landing.

The student pilot carried out a procedure that placed the aircraft in low-energy, weightless flight. The qualified flying instructor unknowingly allowed the aircraft to remain in a weightless state in excess of the time limit prescribed in the CT156 Harvard II Canadian Forces Approved Flight Manual, which reduced lubrication to the critical components of the engine and reduction gearbox. The resulting lack of lubrication caused damage and the ultimate failure of the engine.

Recommendations were made to improve instructor and student training and to increase emphasis and avoidance of critical regimes of flight such as zero-g operations. Changes were also recommended to aircraft maintenance practices involving engine oil consumption monitoring and seat survival equipment packing.

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