Re.: Parachute problems, flight test challenges, and AOA sensors problems (Emphasis mine):
...According to statements from the surviving co-pilot and flight test engineer, the flight crew was troubleshooting a noise associated with stalls conducted during previous flight test activities. A non-scheduled stall was conducted after the scheduled testing and the plane's angle of attack, the difference between the plane's flight path and its wing's chord line, increased past the maximum allowance of 34 degrees.
All is Lost...
The flight crew lost control of the Challenger. Following the recovery procedures set in place, they were unable to regain control, going so far as to, in a last ditch effort, deploy the plane's emergency spin recovery parachute. Control was temporarily regained, but now the deployed chute fouled the flight characteristics. Unable to release the chute, with with the plane's starboard engine failing, the flight crew was forced to bail out of the doomed aircraft.
The plane impacted the desert floor near the village of Cantil at 9:10 in the morning. Unfortunately, the pilot, Eric Norman Ronaasen, was killed when his chute failed to deploy, and the copilot, Dave Gollings, received minor injuries. The flight test engineer, Bill Scott, was not injured
Months after the crash, a Canadair flight engineer examined computer information that had been available before the crash and discovered the banging was caused by an engine problem.
The NTSB, after its investigation, concluded the probable cause of the accident was a problem with the angle-of-attack indicator binding, due to a failure in the seals of the hydraulic system. It also concluded that four separate systems failures had caused the crash - three of which had plagued the twin-engined jet in earlier tests.....
Challenger #1001
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