TWI experts keep flying legend airborne

Nineteen forties engineering and 2011 welding expertise joined forces at TWI recently, in a combined effort to keep the world’s oldest flying jet aircraft in the skies. A thin sheet stainless steel shroud surrounding the jet pipe of a North American Aviation F-86A Sabre jet fighter was in need of some specialist attention when it was delivered to TWI. The purpose of the shroud is to deflect any leaking exhaust gases away from the internal structure during the brief period, between start-up, and the engine reaching running temperature, when previously weeping seals around the jet expand and become leakproof. Although within limits, several small cracks and tears were in need of attention during the Sabre’s annual maintenance if the aircraft was to achieve its Permit to Fly. Because there is no direct civilian equivalent, such historic ex-military aircraft fly under this rigorous permit system rather than the Civil Aviation Authority’s certificate of airworthiness.