My question is really specifically about a lycoming engine in an enstrom airframe. I have been told by a UK instructor that after 12 years they can no longer rent or train in the machine.
I googled and found this which agreed with this back in 2009
http://forums.flyer.co.uk/viewtopic.php?t=55503
I'm not sure how to find out for sure! I'm trying to decide how important this is to me, and when I come to sell the machine once I'm done: and how much this factor should impact the price.
On a personal level I'm also pondering whether a 25 year old helicopter with original engine is a good thing or not!