"Take off skipped - circling". Then crash on t/o

ArduPlane Plane 4.4
1

Crashed on t/o yesterday again. Reviewing the messages reveals takeoff skipped - circling 0.2 seconds after arming.

I then walked it over to the launch site 30m or so. Shook it and launched. A second or two after launch the motor audibly reduces and picks up again moments before impact.

I can see in the log the reasoning. Tecs airspeed was above tecs demanded airspeed however the reality it was was just out of my hand and 1.5 sec power cut.

Anyone have a similar event? I have read some older topics but couldnt see a resolution.

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If you can fly, i recommend getting some time and flights on it in fbwa or even manual. Then once its all flying well and sorted try switching to auto from a safe height and if you dont like what it does go back to fbw.
Early flights where you throw it in auto are risky.

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Hi Rob,

do you fly with pitot airspeed sensor? We notice bad wind and airspeed estimation without an airspeed sensor, i.e. with synthetic airspeed with TECS_SYNAIRSPEED=1, during takeoff. See: Plane: Bad EKF3 wind and airspeed estimation during takeoff with synthetic airspeed - Takeoff problems

Cheers

Friedrich

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Thank you all for the replies.

It looks like i jumped the gun a little with the “take off skipped”. While it did trigger the cause of the throttle coming back looks like an airspeed issue.

The aircraft met the desired speed and throttled back as expected. The takeoff skipped due in part to airspeed indicator readings as i walked to the launch site made worse by poor calibration.

Explanation by Henry at

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