I had the misfortune to have a test cell operator panic during a startup - the engine had preservative oil in it, thus a delayed lightoff and tailpipe fire. He terminated the start then re-engaged the starter - with the result being a sheared tower shaft between the gearbox and core engine. (That's an interesting problem to sort out, BTW - the apparent core rotation on the instruments is simply the starter turning the gearbox, but the engine is disconnected
)
Anyway, no harm done with the low-energy fire in the tailpipe, but we had to fit a new tower shaft...
