Over the next four weeks, Martin-Baker and the JPO will carry out 21 tests at different speeds and altitudes to determine the effectiveness of the changes made and finalize the technical assessment.
In the seat built by the British company Martin-Baker, a "potentially fatal error for the rider's life" was found. This mistake already has a number of potential victims: a third of the pilots who will fly the F-35. In the ejection phase, therefore we are in emergency conditions, the system would cause such a violent whiplash due to an incorrect position of the seat propelled outside the aircraft. The risk, recognized by the Department of Defense, is real for pilots between 60 and 65 kilos.
The Department of Defense is working with Martin Baker and Lockheed Martin on three major corrections: design of a lighter helmet to reduce pressure on the pilot's neck, installation of a system that will delay the deployment of the main parachute and the assembly of a panel support for the head between the parachute risers.
Tests have shown that pilots, whose weight is just under or in excess of 135/140 pounds, have a 98% chance of death during ejections at 160 knots: this is the average speed of a take-off or of a landing. American F-35-enabled pilots who fall into this weight class are steadily increasing. Their license has been suspended and they will continue to fly only on simulators. But the problem may have been underestimated because the risk percentage remains high even for pilots with an average weight.
The Pentagon hoped to solve the problem with some sort of switch. The device, already tested, would have adjusted according to the weight of the pilot. When a lighter pilot sits at the controls, the ejection device delays the release of the parachute by a fraction of a second, which is believed to reduce the impact on the pilot's neck. A support device has also been added between the parachute risers to prevent the heads of ejected pilots from making unnatural and potentially fatal movements.
The two changes, according to the Pentagon, will be in production by the end of 2016. An estimate, the latter, considered too optimistic by Congress, which foresees at least a year of tests and optimizations before large-scale production. The problem with the helmet, on the other hand, will take even longer. A pilot weighing 60 kilos cannot wear the current $ 400 helmet. A pilot with a weight of 60 kilos (tolerance threshold in excess and under two kilos), has one chance in 50 thousand of suffering a neck injury in case of expulsion. Pilots weighing between 63 and 74 kilos have less risk with a one in 200 chance of suffering a potentially fatal neck injury.
Engineers are trying to reduce the weight of the helmet to ward off life-threatening neck injuries for pilots ejected from the aircraft. Helmet (Photo) currently weighs 5,1 lbs. The minimum safety threshold to reduce life-threatening risks is 4,6 / 4,8 lbs. According to the Department of Defense report, helmet weight corrections are at least nine months late compared to the other two solutions identified. It would be fair to note that the restrictions will remain in effect until the three changes are operational. Implementations will take at least a year of testing. The three fixes were expected to be implemented by the summer of 2017. The Air Force, in an email dated January 8, acknowledged that the fixes will be implemented by December 2018.
The Pentagon, meanwhile, continues the technical assessment to determine the cost and impact on programming for a possible transition to the new ACES 5 model from United Technologies. The ACES 5 features a stabilization system the company calls "STAPAC" and a headrest that pushes riders upside down during ejection. Martin-Baker is part of the industrial participation strategy of the F-35 program. If the Air Force opts for the ACES 5 seat, the repercussions in economic terms could be devastating both for the final cost of the aircraft and for mitigating lost revenues. There is already talk of a possible initial loss, if a new seat is chosen, of about 50 million dollars for the four years of testing alone.
(images: Martin Baker / Lockheed Martin)
