So I was making a test flight with my multirotor platform this week using the PX4 stacked setup
and all of a sudden the RC receiver link was lost. Failsafe is set to RTL or land upon low PWM
or no receiver detected. I check if this status message displays with each flight before connecting
motor power for safety and reassurance.
Instead of this, the multirotor pauses as usual before starting the failsafe RTL or land maneuver and
it begins to fly reverse on a very straight course in windy conditions holding a 20 degree pitch angle, suggesting it was following some kind of trajectory. After dangerously traveling some kind of unknown course in a straight path near pedestrians from a previously safe flying area roughly 1000 feet from my takeoff location, it also began to ascend to approximately 250 feet from it's 50 foot altitude~ during this flyaway at the last 200 feet of the 1000 feet of horizontal travel observed. It then suddenly began
to drop at high speed, but with a very low throttle. My guess is a descent speed of 30mph. Luckilyit crashed into a somewhat soft grassy area with minimal damage.
What angered me the most is despite some kind of failsafe occurring, throttle was never cut.
luckily I still had telemetry through at least 300 feet of intermittent foliage. As I approached the
wreckage, there was smoking rising from the grass, but it was only the motors having a massive
overheating which destroyed 2 of them. I was lucky to find it in time and had to carefully work around
an unpredictable array of propellers to pull the battery cable.
In the mission planner screen, it even displayed a crash error, yet throttle was still not cut.
My ESC's have a failsafe so apparently the PX4 was still outputting a high enough PWM signal to keep the motors running. It was also trying to stabilize it's self. The GPS track displayed on the Missionplanner screen was completely accurate, so im doubting the GPS module had anything to
do with the flyaway but I cant rule it out. This event has disappointed me greatly but I don't know where to point my finger.
Can anyone point me to the most popular labels in the log file(which I was lucky to have had enabled) in which I can troubleshoot more effectively? I'm not very good with this. I would post the log file but due to the location of this event, I don't feel comfortable perhaps making a mistake.
Maybe I can extract portions of the logs ? Its the GPS data I rather not share, but of course in
this case can be important for community assistance.