fixed Error in the FMC Yaw channel behaviour in Position Hold Submode.

[TZeer]

There is a bug/error in how the FMC controls the Yaw input on the Apache.

Could you confirm that my observations are correct @Raptor9?

In the manual it states:

 

Quote

If Attitude Hold is enabled in Position or Velocity sub-modes, Heading Hold will engage when all of the
following conditions are true:
• Pedal displacement ≤3% in yaw axis from the force trim reference position in Position Hold sub-mode
or ≤6% in yaw axis from the force trim reference position in Velocity Hold sub-mode
• Force trim release is not pressed
• Yaw rate <3° per second

 

What I observe is that when in Position Hold submode, you need far more than 3% displacement on the pedals to actually break the Heading Hold. It will not dissengage the mode until the input it close to saturated, or roughly 10% displaced. The hold mode will fight you until you are close to the end of the limits of the +/-10% authority.

If I slowly move into 20-30 knots, and transfer into the Velocity Hold submode, I need less pedal displacement to disengage the hold mode. This can easily be observed by just bringing up the control input indicator, and play with the pedals.

Roughly halfway to +/-10% limit the hold mode will disengage, which seems correct as the manual states 6% in the Velocity Hold submode.

 

If my observations and understanding of the systems are correct, we now need over 3 times the pedal displacement in Position Hold submode than what should be necessary to start turning the helicopter.

Due to this error, the apache will "fight" the pilot more than necessary when trying to turn while in Position Hold submode.

Regards

[Raptor9]

@TZeer at the moment there are two bugs related to this that have already been reported:

1. The heading hold breakout values are not present when Attitude Hold (in any sub-mode) is enabled.
2. The heading hold is disengaging when the Yaw axis becomes saturated.

Both of these have been fixed internally but have not made it to Open Beta yet. Unfortunately I do not have any news to share on this, but the Heading Hold and Attitude Hold are still receiving refinements with their logic, which is fairly complex (and interwoven with each other) when you tack on all the other variables with the FMC. But we are aware of the issue and are trying to get these resolved as fast as possible. Thanks.