Failure of 1 motor on quadcopter

Q: How does PX4 handle an ESC/Motor failure on a quadcopter

From @dagar

“There’s some monitoring in commander using ESC feedback. there’s handling in the control allocator that removes the failed motor and recomputes the control effectiveness for example a hex could lose a motor, recompute the “mix” for the remaining 5 and still be functional for a quad it wouldn’t “just work” as is without special yaw handling”

This would probably warrant a SITL test where a motor is switched off using the failure command.