Mission 5
The Motor Failure Investigation
Read the telemetry. Find the fault. Call it.
Difficulty
Briefing
Three incident recordings from the test range. In each, something went wrong with a motor. Replay them (slow motion and rewind are your friends), find which motor failed, work out which way the aircraft yawed, and decide whether controlled flight was possible.
Objectives
- Identify the failed or weakened motor in each case
- Predict the yaw direction from the propeller spin
- Decide: recoverable, degraded, or not recoverable
Physics in play
Moments from differential thrustReaction torque and yawControllability: 4 rotors, 4 things to control
Hampton’s .02 cents
a quadcopter controls four things — total thrust, roll, pitch and yaw — with exactly four motors. Lose one and something has to give. A hexacopter has two to spare.
Instructor insight
It would behoove you to look at the motor speed bars before the 3D picture. The motor that stops responding to its command is your suspect.