Takeoff throttle is not at maximum when Airspeed not used for throttle control

ArduPlane Plane 4.3
1

Hi to All,

I have a catapult launched UAV with no throttle suppress before launch. Airspeed not used for throttle control (ARSPD_USE 0). After switching to AUTO mode with TAKEOFF command the throttle out is not set up to TKOFF_THR_MAX (100%) and in the data flash log I can see it outputs only 89% of the throttle. Before starting, it can reach 100% throttle with manual or FBWA. The log shows that TECS throttle out is at a lower value. I expected that if the throttle is not governed by airspeed then the throttle during takeoff has to be at TKOFF_THR_MAX level until we go higher than expected.

Why it may happen? What I can do to get 100% throttle at takeoff?

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2

This is indeed odd and easy to reproduce.
I’ve created an issue for this while we look at fixes:

3

we have a fix here:

if you would like me to build a test firmware for you please let me know what board you need it for

4

the fix is merged into master, so ‘latest’ firmware will fix the issue

5

Thanks a lot! Do you think it could affect throttle control anywhere else?