Originally Posted by Dani
The TLA engine 2 stays constant. In the CLB detent.
- yes - we know the 'reading' of the position on the FDR, but we do not know for sure the position, and the possibility (in my book the
only other) would be that the signal of TL position was faulty. 'CLB' is where I understand it goes at clean-up and where it stays until it is retarded to idle. Likewise
All TL movements of the last 120 minutes of the flight.
- we know only the 'readings' of that position. The thrust changes are not relevant UNLESS the output of the TLA sensor is accurately feeding information to the engine control. If it was 'broken' (in the 'CLB' sense) then no amount of TL movement would show on the FDR.
Getting well out of my depth now, but I think I saw a hint earlier that a 'jam' of some other unit in the system was a possibile extra avenue to explore.
My personal (NB non-mod hat on) opinion is that the failure of what I understand to be 2 sensors is so unlikely as to be dismissed, so I go for human error and confusion.