Everytime I reboot (4.6.3, non-vectored VTOL), Servo 3 and 4 change to TiltMotorFront (right/left)

[wsalopek]

Bug Report

Bug report

Issue details

Please describe the problem

https://discuss.ardupilot.org/t/everytime-i-reboot-servo-3-and-4-change-to-tiltmotorfront-right-left/143041

I change servo 3 and 4 to disabled - but when I reboot, they are set to TiltMotorFront (right/left).

To be more clear, rebooting does NOT change the servo outputs, but power cycling DOES.

Version
4.6.3, 4.7.x beta, and tried all the way back to v4.2.x(?) - two different flight controllers.

Platform
[ ] All
[ ] AntennaTracker
[ ] Copter
[ X ] Plane
[ ] Rover
[ ] Submarine

Airframe type
What type of airframe (flying wing, glider, hex, Y6, octa etc)

I’m building a 2-motor, non-vectored tailsitter.

Hardware type
What autopilot hardware was used? (Pixhawk, Cube, Pixracer, Navio2, etc)

Kakute F7 (non, AIO), and Pixhawk v1.1

Logs
Please provide a link to any relevant logs that show the issue

[IamPete1]

That is expected. So long as Q_TAILSIT_VHGAIN is zero it will have no effect in flight.

[wsalopek]

Thanks Pete - so now I can relax.

IMHO that behavior should be corrected.

I spent OVER A WEEK trying to track this issue down (didn't even know I could post to Github (my fault), and was using the Ardupilot forums) - the issue is QUITE unintuitive, IMHO, as well as dangerous, because in fact, my Q_TAILSIT_VHGAIN was set to .5 - so if I had attempted a takeoff, who the heck knows what would have happened.

Anyway again, thanks, it might be "expected" behavior (given the state of the firmware), but it's not normal to have your servo assignments changed (is it?), and certainly not to something quite possibly dangerous.

At the VERY least, if the firmware is going to be changing servo assignments on a power cycle, the firmware should also set any OTHER values so as to make operation safe, in this case, the Q_TAILSIT_VHGAIN value set to ZERO.