6 point Accelerometer Calibration in a Bixler 3 (Chibios on Omnibus F4 Pro V3)

I have a Bixler 3 (that has been converted from iNav) running an Omnibus F4 Pro V3 flashed with AP 3.9. As the FC is well mounted in the plane and it is a PITA to remove and calibrate, I wanted to just level the plane with spirit levels and simply do a 1 Axis level calibration. This should be ok, right?

Any (informed) opinions here? Surely I do not have to remove it and do a 6 point calibration and then place it back.

you don’t need to remove the FC to do the 6 point cal. It is easy to cal a bixler.
One thing a lot of people don’t realise is the “put right side down” etc part of the cal isn’t exact. It is OK if its within 15 degrees or so. It just needs to be not moving.
The only step where it does need to be level is the first one, where it asks you to place it level.
But to answer your actual question, and one-point cal is usually OK. Whether it is OK depends on your individual sensor, and whether that sensor has large scale factor errors. Most modern IMUs are OK, but you do get individual ones that need the full cal. Also, it depends a bit on how you fly it. If you are planning to fly it hard then a 6 pt cal is more worthwhile than if you are just tootling around the sky gently.
Cheers, Tridge

Brilliant. Straight from the horse’s mouth (no ordinary equine either!)

Tridge, thanks for taking the time to answer a question that has kept me
awake at night. I have never had a really good answer to this and many
experienced Ardupilot people are actually unsure about it. So basically a
proper level calibration and other axes it will suffice to have the wings
flat against the wall. I was never happy with my Irish contractor but I am
assuming he go my walls within 15 degrees of vertical.