Usually when flying this drone we are using RTK (moving baseline) with the two CUAV F9P GPS modules, and we use the GPS yaw/heading. Under good conditions, the GPS statuses are 3D dgps and RTK-fixed.
Here is the configuration onboard the Cube Orange autopilot in ArduPlane parameters:
GPS_TYPE = 17 , GPS_TYPE2 = 18, EK3_SRC1_YAW = 3 .
I conducted a series of 10 consecutive 5 minute tests on the ground (propellers removed, arm the drone, switch into AUTO mode) during which the problem would’ve occurred with the previous parameters, except now with the parameters adjusted as follows so that the drone does not use RTK.
GPS_TYPE = 1 , GPS_TYPE2 = 1, EK3_SRC1_YAW = 1 . The GPS statuses were now both 3D dgps (so no RTK used).
RESULTS:
Arm test 1 - GPS fine, no problems
Arm test 2 - GPS fine, no problems
Arm test 3 - GPS fine, no problems
Arm test 4 - GPS fine, no problems
Arm test 5 - GPS fine, no problems
Arm test 6 - GPS fine, no problems
Arm test 7 - GPS fine, no problems
Arm test 8 - GPS fine, no problems
Arm test 9 - GPS fine, no problems
Arm test 10 - GPS fine, no problems
The problem did not happen during these tests when RTK was not used.
For comparison, this is what the problem looks like on the [ground](WhatsApp Video 2023-06-17 at 15.33.50.mp4 - Google Drive and WhatsApp Video 2023-06-17 at 15.33.47.mp4 - Google Drive ). And in flight 1 and flight 2.
This leads me to believe that there is a compatibility issue between Ublox F9P receivers with 1.13 firmware and ArduPlane v4.3.5 / Cube Orange. This appears to be a similar problem to this one, which was resolved by upgrading the firmware on the F9Ps from 1.12 to 1.32.