Lyman
Re: Thales Cleared
I don't think so.
What would the AutoFlight do? Decrease thrust, and PITCH DOWN, Another result? WIND SHEAR, and TCAS action.
@ Just prior to
2h 10min 0sec, they are cruising in A/P A/T @ 282 CAS and a Mach of 0.82
@
2h 9min 58sec,
the speed handling is change (
probably by the PNF, my words) from managed to selected. The selected Mach is 0.80, the turbulence penetration speed.
@
2h 10min 0sec, the pitch attitude decreases from 1.8° NU to 0° in 3 seconds and the engine N1 begins to decrease from 100% to 84%, reaching 84% in 8 seconds.
This was accomplished by moving the thrust levers while remaining in A/T, my words
@
2h 10min 03sec, the nacelle
anti-ice switches for the engines are changed to ON.
@
2h 10min 05sec, the A/P2 disconnects. The roll angle changes from 0 to 8.4° in 2 seconds but the sidestick is a neutral. The pitch atitude is 0°.
@
2h 10min 06sec, the flight control law changes from normal to alternate.
@
2h 10min 07sec through
2h 10min 18sec, the copilot sidestick is positioned:
- nose up between neutral and 3/4 of the stop position
- to the left in half-travel position then to the right in half-travel position and twice, alternatively left to the stop position then right to the half-travel position.
- The pitch attitude increases to 11°
- The vertical acceleration varies between 0.9 g and 1.6 g.
-The roll angle fluctuates between 11° right and 6° left.
- The vertical speed increases to 5200 ft/min.
@
2h 10min 08sec, the FD1 and 2 become unavailable. The
A/THR disengages and the
THR/LK mode is activated. The N1's are 83%. The CAS changes from 274 kt to 156 kt. The CAS ISIS changes from 275kt to 139 kt then goes back up to 223kt. The Mach changes from 0.80 to 0.26.
Now I am going to skip a little bit to around
2h 10min 17sec. It is here they recognize the THR/LK is active.
I think shortly thereafter then they reset the thrust levers back to 100% N1 as depicted on the chart, my words.
So you see, the speed changes were made by the pilots not the A/THR. They also recognized there was the likely presence of ice or they would not of turn on the nacelle anti-ice. This recognition came a little late and was probably due to the use of the weather radar. They had it set on a long range ND and reduced it several times which lead to the request by the PNF, "You can maybe go a little to the left I agree that we're in manual, eh?" The magnetic heading selected decreases to 34° from 35.5°. The pitch down may have resulted from the decrease in Mach and the roll back of the N1 from 100% to 84% and was only from 1.8° to neutral.
The roll tendency is interesting, something that I can't explain other than the weather situation at the time.
These are my thought, I think the pitot tubes icing started the event as they entered a weather system perhaps they should have avoided.