Business aviation operators need “to focus on high-altitude stalls” in upset prevention and recovery training (UPRT), due to the effect of reduced air density on aircraft performance and aerodynamics, said John Cox, CEO of Safety Operating Systems, last week at the Business Aviation Safety Summit (BASS) in Phoenix. “The instability [at high altitude] is something we’re not adequately addressing,” he said, noting many pilots have no experience hand-flying aircraft at high altitudes due to RVSM mandates on using autopilots above FL290.
The loss of control accident in January over the Arabian Sea involving a Bombardier Challenger 604 at FL340 underscores the need, he said. The Challenger rolled several times, following a wake encounter with an A380, and reportedly lost 10,000 feet of altitude before recovery. The episode resulted in serious injuries to passengers and the permanent grounding of the aircraft as a result of damage from exceeding operating limitations.
When properly executed, “high altitude recoveries are slow and gentle,” Cox said. Paul Ransbury, president of UPRT provider Aviation Performance Solutions, who’s discussed the accident with Bombardier investigators, told attendees that they declined to say whether the Challenger crew had undergone upset recovery training.