"Peter" wrote in message
...

"BT" wrote

In the US, a non certified engine into a "standard" certified aircraft
could
impact (limit) the future use of that aircraft to non commercial
applications.

I think it would be a bit more serious than that

True.. putting in an engine that is outside of the TCDS will require
paperwork, 337 field approval and all of that.
If there is already an STC for that engine in that airframe.. it's a tad
easier..
But in any case.. a non certified engine.. even if approved for
installation.. could remove the aircraft from commercial services.