The throttle idle speed is high.

PX4 Autopilot
1

In the latest firmware version 1.15.4, I simply can’t find the throttle idle parameters. As a result, the aircraft starts ascending as soon as I arm it, and I can’t make it descend. In the end, I had to resort to a crash landing. Its idle speed is extremely high. I tried calibrating the ESCs, but it didn’t work either.

2

I was going to say ESC calibration and/or adjusting the idle speed using the parameters, e.g. if connected on Aux: PWM_AUX_MIN1. Easiest to adjust in the QGC Actuators config panel.

I suggest to try it out in small steps:

  • Remove props and try out parameters.
  • Put props back on and strap drone down (e.g. with a short rope) to test it.
  • Fly again.

And, always have a kill switch configured for initial tests like that to cut throttle immediately when things aren’t good.