Did the NTSB not state in one of their briefs that the engines responded normally to all inputs by the pilots? This info can only have come from the FDR.
So, how about levers in IDLE as they capture from above, as they descend through the profile the levers are moved forward (as claimed by the crew) but even though they're at (approach) idle the response time is still relatively slow. The crew think (erroneously) they're not responding and close the levers to "try again". Repeat several times with the thrust barely going above idle and the perception is that the system has "failed" - only when they TOGA does the system "work".
What's the spool time from idle on 777 compared to the A320? Does the 777 have "approach idle"?
I offer this purely as a theory as to why the crew believed the thrust was not available.
Last edited by A4; 15th Jul 2013 at 07:37.