Hi,
when programming AP mode using as input offset $3070 (Z (longitudinal, or forward/backward) acceleration in ft/sec/sec) I've found strange behaviour of this offset:
If aircraft is on ground, parking brake set and not moving, this offset oscillate around values 0.57 - 0.58ft/s/s
Such value is not a low deviation - comparing to take-off run or intensive braking when value of this offset is around 10-11ft/s/s
Only in case I shut down both engines, this offset will came close to 0.
Values are from FSinterrogate from Flight1 ATR72 plane, FSUIPC version 4.60a
Could I please get some explanation of this behaviour? Only one possible coming to my mind is vibration from engines.
Thank for any help.
BR
Litin