Perception and Fatigue: CH124 Sea King Engine Shutdown
The Royal Canadian Air Force (RCAF) have reported on an incident during training of a new Maintenance Test Pilot (MTP) that lead to an engine failure on Sikorsky CH124 Sea King CH12428 on 11 May 2015 over the Strait of Juan de Fuca, South of Victoria, British Columbia.
During the conduct of the number one engine manual throttle topping check, the MTP Trainee inadvertently bumped the manual throttle slightly forward and had to re-establish hand position on the manual throttle lever.
The investigation determined that the AC [Aircraft Commander] misinterpreted the motion of the MTP Trainee gaining a better grip on the manual throttle control lever as the MTP Trainee closing the manual throttle.
This perception error led to a cascade of subsequent events, which began with the act of lowering the collective and resulted in engine failure.
They go on to say that:
The Royal Canadian Air Force (RCAF) is currently in the process of implementing a Fatigue Risk Management System (FRMS), which will be a multi-layered approach to preventing fatigue and managing fatigue-related risk.
Full implementation of the RCAF FRMS is anticipated for mid-2017. Fatigue-modelling capability and FRMS are being developed as components of the RCAF Mission Acceptance / Launch Authorization (MALA) risk management tool.
Although not directly causal to this occurrence, collateral findings and recommendations were also made regarding Aircraft Operating Instruction procedures and cautions for operating the manual throttle.
The RCAF provide no further information on how the fatigue occurred or the specific engine damage.