marciovp,
As PBL has already pointed out, making observations about event timing at a precision higher than the sampling rate is impossible, maybe we should hold a short course "Reading Time-Discrete Data Plots". Drawing a linear interpolation between the points implies a continuity in the data that's not there.
I'm also not sure what point George Rochas is trying to make.
There are some points to consider about autothrust operation:
- Thrust in engine #1 was reduced
- Slightly before the dramatic increase around 18:48:26, there is a notable drop in longitudinal acceleration at 18:48:24.2, corresponding to a recorded drop in speed around the same time
- Autothrust is especially responsive to speed variations during approach, trying to compensate quickly even for small deviations, since approaches are usually flown rather close to minimum speed. This submode of operation is known as "approach autothrust", in this mode, precise speed-keeping has priority over comfort considerations, safely to keep the speed above stall speed.
Taking this into account, the reaction of the engines is perfectly normal.
Even with two engines operating, sudden thrust increases shortly before touchdown are not unusual, especially in gusty conditions. Again I recommend watching some landing videos, youtube has a wide selection.
My impression is that George Rocha, this talented Jet pilot feels that the software did not work very well because even eith the LEFT motor reversed and the pilot aplying brakes, it still behaved as if the plane wanted to go around
Yes, this has been widely discussed here, almost from the beginning. The problem still being that the aircraft cannot read the pilot's mind so has to follow control inputs, because there is no obvious
Right Thing to do.
And the aircraft was not behaving as if it was tryng to go around; going around requires a whole different region of thrust, closer to sustained EPR 1.4, and not a peak at 1.26, and then settling at 1.18.
Bernd