The UAV crashed. The search for the cause

My UAV has crashed and I can’t figure out why.
I created a mission flight and loaded it into the UAV. Then he turned on the AUTO mode.
The UAV normally took off, but then headed in the other direction, picking up speed and falling. I executed the RTL command, but it didn’t affect in any way and it fell.
Studied the manual
In the last flight, the take-off point was 10 meters from the road, 30 meters from the wiring line, and 30 meters away there were 2 telephone towers. Up to this point have produced automatic flight on the same field, but farther from sources of electromagnetic interference.
Can anyone help me with log file analysis? Files attached to the message.
I use pixhawk 2.4.8

With the help of Mission Planner I did an auto-analysis and here is its result:

Auto Analysis
Log File C:\Users\6385\AppData\Local\Temp\tmp5A33.tmp.log
Size (kb) 31492.716796875
No of lines 381836
Duration 0:24:44
Vehicletype ArduCopter
Firmware Version V3.5.4
Firmware Hash 7703ca88
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = UNKNOWN - No ATUN log data
Test: Brownout = GOOD -
Test: Compass = FAIL - Large change in mag_field (101.55%)
Max mag field length (769.58) > recommended (550.00)

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: IMU Mismatch = WARN - Check vibration or accelerometer calibration. (Mismatch: 1.06, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = WARN - Motor channel averages = [1491, 1508, 1452, 1541, 1529, 1467]
Average motor output = 1498
Difference between min and max motor averages = 89
Test: NaNs = GOOD -
Test: OpticalFlow = FAIL - FAIL: no optical flow data

Test: Parameters = FAIL - ‘THR_MIN’ not found
Test: PM = GOOD -
Test: Pitch/Roll = GOOD -
Test: Thrust = GOOD -
Test: VCC = WARN - VCC min/max diff 0.352881 v, should be <0.3 v

It turns out the problem is in the compass? But why then the UAV has passed pre-flight checks and carried out takeoff? As henceforth avoid such drops: use 2 compass? Is there a device that determines the level of magnetic interference with which you can find out whether the pixhawk autopilot can fly in these conditions?

00000026.BIN (292 KB)

Looks like you have some instability problems. Both roll and pitch are not matching desired values.
Motors are running quite above 50% throttle (suggested for good margin). It seems your copter is underpowered.
In more than one occasion two motor reaches maximum: this condition should never happen.
Vibration could also be lowered with better damping.

Hope this helps


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