I'd be surprised if it had anything to do with the manual mode with the ITT up there for that long. I could see an inadvertent overspeed in this mode but even then not for that amount of time without recognition.
I had an engine fail a few years back on a AW139 on taxi, the ITT maxed out after the engine failed and dry motoring the engine made absolutely no difference to bring the temp down. However the engine reached 1000 degrees in a matter of seconds after the failure so the engine was finished, motoring or not. Turned out the problem was caused by the engine driven fuel pump pretty much seizing up which obviously dragged the Ng down. I think if I remember the ITT was recorded by the as above 900 for more than 20 seconds.
The only other instance I have heard of ITT getting into that range for that amount of time was during a botched manual mode restart.
Who knows what happened as I wasn't flying, but I sure there is a logical explanation to what happened and I'm sure we'll all hear all about it before long.
Last edited by platinumpure; 2nd Dec 2010 at 17:13.