Thanks, guys, I've now been and searched for CAP520 and read it. They don't make things easy to understand. do they. If I churned out something like that at work it would be bounced right back to my desk. I don't have any local maintence people to ask any more - it's a case of talking to someone I really don't know, and I'd rather have a vague idea of what the requirements are before I start. Seems to be a check every 50 hrs (do they get more onerous - bit like car service intervals where each one covers a bit more than the last?), an annual (which can coincide with one of the others?) and the CofA every 3 years, then pass go and start again. Does that sound about right?