Commission of Inquiry report released into CH-47D Chinook crash
18 December 2014
Defence has released the Commission of Inquiry report into the circumstances surrounding a fatal helicopter crash in Afghanistan on 30 May 2011. Lieutenant Marcus Case was killed when he was thrown from an Australian CH-47D Chinook helicopter during large and uncommanded pitch oscillations, colloquially known as ‘porpoising’.
Lieutenant Case was a passenger, travelling on the Chinook's ramp at the time of the crash.
Army took immediate action to address safety issues as they were identified. In addition, Defence and Army have undertaken a considerable amount of work since the accident to improve Chinook training and airworthiness as well as general aviation safety management.
In total, 71 recommendations and initiatives have been implemented as a result of the Commission of Inquiry and Aviation Accident Investigation.
The Commission of Inquiry was appointed to further inquire into certain aspects of the helicopter crash, following the completion of a technical investigation conducted by an Aviation Accident Investigation Team from the Directorate of Defence Aviation and Air Force Safety.
The Commission of Inquiry was conducted to inquire into the primary and contributory factors that caused the accident and Lieutenant Case’s death, while the primary purpose of the Aviation Accident Investigation was to identify any aviation safety issues arising from the accident.
Together, these two inquiries comprehensively answer the technical questions associated with why the aircraft crashed.
The Commission of Inquiry identified the following factors led to Lieutenant Case’s death:
- the CH-47D helicopter was susceptible to pitch oscillations during operations at high density altitude,
- pilots believed the Advanced Flight Control System (AFCS) could correct all pitch disturbances,
- in the absence of any formal advice or training, the pilot and co-pilot responded incorrectly to the uncommanded pitch oscillations,
- contrary to Army policy, Lieutenant Case was permitted to ride on the ramp, and
- Lieutenant Case’s restraint strap becoming fully extended during the pitch oscillations.
Defence agreed to all 19 recommendations from the Commission of Inquiry report and all of these have been fully implemented. The recommendations include issuing a more comprehensive Army Directive on carrying passengers and cargo in all Army operated aircraft, reinforcing the need to report incidents, education about the limitations of the AFCS, and removing the restraint strap from ADF service.
In February 2012, Army accepted all 35 of the Aviation Accident Investigation report’s recommendations. In addition, another 17 initiatives were proposed by Army aimed at improving Chinook aviation safety.
The Aviation Accident Investigation recommendations included:
- improvements in training, policy and guidance to address uncommanded and divergent pitch oscillations,
- improved guidance on CH-47D ramp operations, and a review of aircrew and passenger restraints.
Specifically, Army Aviation invested considerable effort in developing a detailed understanding of the CH-47D handling qualities. This included a collaborative Defence Science and Technology Organisation and Army project to develop a pilot-level training document addressing the more complex issues associated with CH-47D operation.
Defence acknowledges the ongoing effect of this tragedy for Lt Case's family, friends and colleagues and continues to support them.
The redacted Commission of Inquiry report is available at: http://www.defence.gov.au/publications/coi/
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