In the UK, extension of up to 20% is allowed on condition for public transport or aerial work.
This is known as operating 'On Extension'. (I dont think that Rotax engines are allowed to be 'Extended'.) Any further operation after any 'Extensions' to the hours,
or calendar times are used up, is known as operating 'On Condition'.
Is it legal (in EASA country) to use an on condition engine...
Yes
...commercially, for example in a rental plane?
No
MJ
