We had a forced break in the project! 🙁 In the process of tuning the electronic system for maintaining the speed (tutor), an attempt was made to “unauthorized takeoff” of the apparatus. Since we did not plan to lift the aircraft into the air at this stage of testing, we did not fully adjust the aircraft stabilization system in the air. And the reverse was turned on in the lateral control channel. When the stabilization system was turned on, it determined that the apparatus was tilted and gave a command to the propellers to align. But since the reverse was turned on, the system worked the other way around and turned the device over. 🙁
We didn’t expect this. Since, according to our calculations, the propeller thrust should be sufficient with one engine for takeoff only without a pilot. And we had a pilot in the vehicle and an additional safety weight – about 120 kg. That is, additional over 200 kg!
But nevertheless, the device turned over! 🙁
As a result, the shafts of the gearboxes and the propeller housings were damaged. The blades are completely broken. And we had to deal with the manufacture of new parts. Unfortunately, it took quite a long time. But finally we finished making new parts, assembled the apparatus, and continue testing and tuning.