Martin-Baker Criticized By Red Arrows Accident Inquest

 - February 7, 2014, 10:10 AM
The Royal Air Force's Red Arrows perform at Farnborough. (Photo: David McIntosh)

The stellar reputation of Martin-Baker (M-B) for saving lives has been tarnished by the inquest into the death of a UK Royal Air Force Red Arrows pilot. Flt. Lt. Sean Cunningham was killed on Nov. 8, 2011 when the M-B Mk 10B ejection seat in his BAe Hawk T.1 jet trainer accidentally fired on the ground, and his parachute failed to open. The coroner who officiated at the three-week inquest returned a “narrative” verdict that cleared the pilot of blame but was critical of M-B and the RAF.

The accident was caused by failure of the safety pin in the ejection-seat handle to prevent the seat from firing. Cunningham had incorrectly fitted a leg strap on his harness before a previous flight, causing the pin to move so that only a slight further movement of the handle was required to initiate an ejection. The coroner criticized the RAF for failing to brief pilots and ground crews about potential problems with the pin. After the seat fired, the parachute drogue shackle failed to separate from the scissor shackle, thus preventing the main parachute from deploying because a locking nut had been over-tightened.

The coroner also criticized M-B for “a very serious failure of communication.” The inquest heard that M-B had alerted five other Hawk T.1 customers about excessive tightening of the shackle bolt on the Mk 10B seat.

In its report on the accident, the UK Military Aviation Authority said there was a “latent vulnerability in the escape system design and maintenance procedures and…an unnecessarily rushed aircraft start-up sequence.” It also noted that “potential failure mechanisms relating to the fitment of the scissor and drogue shackle assemblies had been clearly identified and acted upon by some parties as far back as 1991.”

M-B said it is “deeply saddened by this terrible accident.” The company noted that a new type of shackle bolt and firing handle housing had since been developed and approved for the Mk 10. It continued: “Martin-Baker is proud to be able to say that, since 1946, it has led the world in the design, development and manufacture of ejection seats. These seats have saved 7,436 lives, seven in [January] alone.”