> There was corporate conversational knowledge that unlocking the feather system during the transonic region would be catastrophic, but this knowledge wasn't formalized into the pilot handbook or in training. There was formal knowledge that unlocking late would lead to a flight abort, and a recent event had occurred where the unlock was late. Add to this copilot workload increases between flights, the fact that training wasn't done in the suits and equipment worn on the real flight or under the g and vibration loads in the flight, and the result was the copilot unlocked the feather early leading to the loss of the vehicle. As usual, not a single failure, but a chain of smaller failures - lack of formalization of knowledge, lack of training in the operational environment, recent events, pressure to avoid an abort, and you get an overcompensation.

> "On normal rocket-powered flights, checklist procedures called for this step to occur after rocket motor burn out while in space just prior to apogee."

I still haven't seen any information on exactly why this particular flight test card called for actuating the feather mechanism at some time other than apogee. Were they trying to test the flying qualities while feathered at a particular dynamic pressure? It doesn't make any sense for the copilot to move the unlock lever while the aircraft was still accelerating unless the test card called for it. And if it did, then did the engineers and test planners fail to take this possible failure mode into account before the flight?