The inquest into the death of Red Arrows pilot Sean Cunningham heard that life critical safety warnings about ejection seat maintenance were first issued to foreign air forces more than 20 years ago, but not the Ministry of Defence.
Seat manufacturer Martin-Baker Aircraft Co. Ltd advised the Pakistan Air Force in 1990 not to over-tighten a key nut and bolt in the seat mechanism.
Over-tightening can cause pinch and lead to the parachute failing.
The instruction was to ensure some free play in components and have one to one-and-a-half threads showing through the nut.
Similar advice to other air forces including India, Italy and Finland followed.
Richard Seabrook counsel for the Coroner, put questions to Michael Cameron, Martin-Baker’s senior after sales executive, who was the company’s chief technical instructor from 1999 to 2008.
Mr Seabrook asked him: “You cannot explain why advice particularly relevant to the MoD was not communicated to the MoD at or about the same time [as foreign air forces]?”
Mr Cameron replied: “I cannot explain this but it was nine years before I got there.”
Mr Cameron said that until Flt Lt Cunningham’s death he was unaware of the risk of the mechanism pinching if over-tightened.
Bernard Thorogood, for the Health and Safety Executive, said the concern about over-tightening was a “risk to life” issue.
Mr Thorogood asked Mr Cameron: “There was concern in 1990 about the thorny issue at the heart of this inquest.
“This should have been passed onto customers?”
Mr Cameron replied: “Yes.”
Mr Thorogood then put to him: “This should have been dealt with in a way that left customers in no doubt?”
Mr Cameron replied: “Yes, but I was not there at the time.”
The court heard that after the accident it was discovered the key bolt in the mechanism in Flt Lt Cunningham’s ejection seat appeared to have bent in operation.
Asked what conclusion he drew from this, retired Martin-Baker engineer Neil Mackie, who worked in its quality assurance department, replied: “Vastly over-tightened.”
Flt Lt Cunningham died after his ejection seat fired from his aircraft while it was on the ground at RAF Scampton on November 8, 2011. His main parachute failed.
The inquest continues.
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Sean Cunningham inquest: foreign air forces were given ejection seat safety warnings more than 20 years ago, but not the RAF | Lincolnshire Echo