ORIGINAL: pauls Microjets

Chaps, i've just spoken to Phill and he's given me these details of what appears to happened/caused the failure.

The starter motor bendix seems to have failed to disengage from the compressor nut, this motor has acted like a generator and fried the ECU,
at the same time it would have taken the load off the preload spring causing the rear bearing to fail, the starter motor has
also failed due to the high speed it would have been taken up to (electric motors don't like being taken to high RPM)
the turbine disk is in one piece and has NOT seperated although there are several blades missing which is what any engine will give in a rear bearing failure, that or the tips of the blades will be ground down severally

these are some of the facts of this wasp failure, the cause could have been from the following,these are the 2 possible causes of this engine failure that i can think of. :-

1: ECU fails to disengage power to the starter motor.......which would cause:-
starter motor goes overspeed and acts like a generator overloading ECU, at the sametime
the starter causes an underload of preload causing rear bearing failure, starter goes too fast and fries it's bearings


2: Starter motor bendix shaft has a fault and fails to disengage from the compressor........which would cause:
starter motor goes over speed and acts like a generator overloading ECU, preload overload and rear bearing skids causing rear bearing failure and the starter goes too fast and fries it's bearings.


my guess is it was the ECU.
the reason i say ECU is because i've never heard of a starter motor bendix failing to disengage from the compressor nut.
if it's happened in the past then i haven't heard of it.

hope this helps to give you some ideas of the fault, i leave you to make up your own minds.

ORIGINAL: Rutter The Nutter
....Well I've just heard it didn't go very well as they struggled to get it running then it blew up in an airframe after 4 mins flying