I was working as Tower controller with a trainee the other morning when a four engined turbo prop aircraft landed.The aircraft taxiied past the tower and we observed that it had one of the four engines closed down.I was a little puzzled as I did not expect it.The trainee was even more puzzled that I did not know what was happening(aren't mentors required to know EVERYTHING?
).I know that there was an elegant sufficiency of serviceable engines still running but might it not be policy to mention to ATC that you are closing one down as a precaution(Obviously if you have two ..or ONLY ONE
the situation would have been somewhat more urgent!)Thanks for any replies.