Quadplane forward throttle does not spool up in auto transitions [issue]

ArduPlane Plane 4.5
1

Platform:

  • ArduPlane 4.5.7
  • Quadplane VTOL 4+1

Issue:

During AUTO and CRUISE transitions, the pusher motor spins up to approximately 25% throttle and stays there during the airspeed wait phase. The aircraft does not accelerate forward, instead it drifts around unpredictably and never builds enough airspeed to complete the transition. The aircraft seems to do this indefinitely until the pilot intervenes.

Transitioning to FBWA works correctly every time.

Param file and flight log are available here:

Graphing RCOU.C13 (pusher throttle), TECS.sp, TECS.spdem, CTUN.As, ARSP[0].Airspeed, and GPS[0].Spd during both auto and CRUISE transitions:

Screenshot 2026-06-02 124522
Screenshot 2026-06-02 1245223256×864 385 KB

Screenshot 2026-06-02 123657
Screenshot 2026-06-02 1236573257×900 435 KB

2

Why are arming checks disabled?

The throttle is limited in auto throttle modes such as AUTO and CRUISE because you have set a power limit of 750 w with BATT_WATT_MAX, with the VTOL motors the power draw is a bit over 1000w, so the max forward throttle is limited to 25%. Manual throttle modes such as FBWA bypass the power limit.

My advice would be to turn off the power limit (and turn on arming checks)