I have a large octo With powerful motors. It's been in the air many times.
I did some work on it today, changing the camera gimbal. I also installed a New 5,8ghz video tx and a trigger Circuit for operating the shutter on the camera. The shutter and video tx were both Connected to the camera. Shutter was Connected to ch6 on the receiver.
I decided to Power it up in the office to adjust the camera shutter channel and test that everything worked. The telemetry system(Frsky Taranis) warned about low RSSI. Since the only new Connection I had made to receiver/apm was the shutter cable, I removed the servocable from the receiver ch6. The telemetry system stopped warning about low RSSI. So, just to check again, I reconnected the servo cable to ch6. I know I should not do this kind of stuff on a live machine With propellers, and luckily I was taking precautions by keeping out of Reach of propellers. Then all hell broke loose...
8 Heavy lift motors With large APC propellers, capable of lifting a total of 20kg went into full throttle. I just let it go and took shelter, while the machine was doing its thing to the ceiling and Office Furnitures, before shutting Down. Most of the propellers and one motor destroyed. Glad to be alive With all my body parts intact. I've been working on multirotors since "the beginning", and had my share of propeller cuts, but thats a long time ago.. It's obvious I needed a reminder again... :)
So... what happened? I'm not concluding With anything, this may not be related to the APM at all. I suspect that the camera shutter in some way made the receiver bring channels high/low. Logfile Attached. Anyone care to do some analyzing?