Three engine failures
OH-58A when I rolled the left hand throttle to idle just a bit too briskly, and the fuel control wasn't set right and the engine flamed out (unannounced engine failure on takeoff along a runway for a student who was doing very well).
Couldn't figure out why there was a beeping noise with the collective full down until I saw the oil pressure drop to zero..
No damage.
Canadian version of CH-46 - following practice engine failure on #1with correct checklist procedures, downwind in traffic pattern / circuit, instructor says "Around here, following a practice engine failure, we put the 'bad' engine throttle up to about 85-90% N1 in case the good engine quits". I nod agreement that this is a good idea, which was followed almost immediately by #2 eating itself up. Not sure who got #1 throttle to fly, but in following 30 seconds we managed to regain composure, shut down #2, restart our hearts and do single engine landing. No damage, except to #2 engine.
Hangs head in shame having joined club that I'd much rather not be a member of - S-55, front tank with 55 gallons, burns 45 gallons per hour, airborne 45 mintues, engine quits due to lack of fuel. Shameful part is twice in previous 10 minutes SSV (still, small voice) had said "switch fuel tanks", and I hadn't listened.
Minor damage to airframe, moderate damage to ego.
In all three cases, I was obviously not expecting an engine failure, and it did take me quite by surprise. Not sure that one second intervention time is a long as it needs to be.
Definitely not like the way we'd practiced in any case.