I rejoin the fray after PJ2 has broken silence, and A333Z continues to provide detailed diagrams and systems info. Attaboys all around. And I think some of the inputs from we non-commercial drivers have helped. At least I hope so.
While wondering what the final report will conclude, my personal feeling is it will come down to training and stall recognition/recovery by HUMANS, not the machine.
- From the data traces I see no extraordinary efforts by the crew to recover from a stall such as using flaps, spoilers, etc. In other words, I do not think the crew knew that the plane was fully stalled, and the control inputs do not reflect appropriate stall recovery techniques/procedures.
- I flew the Deuce ( F-102) early in my career and it had no obvious stall entry warnings or "feelings". All that happened was the jet began to descend rapidly ( sink rate) and it had exceptional directional stability. Seems the Concorde had similar flight characteristics.
Recovery was very easy. Move the stick forward/relax back pressure in order to reduce AoA . Additional power helped, but the underslung motors on the 'bus seem to induce a nose up moment versus the centerline motor of the Deuce. Same true for the Viper, and the thing would simply start to descend with full back stick pressure once it reached the design AoA. Unless that puppy was in a deep stall, then recovery was the same - lower the friggin' nose!
- While looking at the reports and data, I conclude that the 'bus is a very stable and well-designed jet. So a stall may not be easy to recognize, especially if the crew is trained that "you can't stall this airplane". FBW and "protections" for another time, another thread, IMHO. But it may come up in the final report.
So I will make my prediction that the final findings will conclude:
- Crew applied inappropriate control inputs for the existing flight condition when data was lost ( regardless of the failures of sensors and such)
- Flight instrument displays and aural warnings were confusing.
- Crew entered a stall and did not recognize the stall nor apply appropriate control inputs to recover. In other words, the plane did exactly what the crew was demanding.
- The report will demand better training and crew coordination during unusual flight conditions.
Am I way off base?