Engine change

[Marc Zeitlin]

What you need to do will depend on what it says in that particular airplane's operating limitations that were issued to it along with its airworthiness certificate.

Exactly so. Those are the ONLY reference for actions after a Major Change, which an engine change most definitely is.

This will vary depending on when the limitations were issued. If the airplane you are describing still has the operating limitations that were issued in 1971, it will undoubtedly say that the FAA has to be notified and their response received in writing before operating the aircraft after making a major change.

I can't say that I've ever seen OL's from the early 70's, but the ones I've seen from the late 70's and early 80's actually invalidated the AC in the case of a major change and required a new AC be issued. I don't know that ALL OL's said that, but the ones I've seen did.

Now, this should have been done when the airplane was modified with the O-290 in place of the O-235! I'm guessing it wasn't done.

And I would say that you're most probably correct - I cannot claim that the aircraft that I've seen with those OL's (need new AC) have not had major changes, but it's a rare case where a new AC was issued due to one.

However, if you are essentially returning the airplane to its already-tested configuration (assuming you'll install the O-235 with the same make/model prop it had originally) then no additional testing would be required, and thus no contact with the FAA would be necessary.

This is incorrect. A major change is a major change, even if you're going back to an identical configuration that was previously tested and signed off (unless the OL's were written from the latest 8130.2H Order). This has been decided in court - see:

http://caselaw.findlaw.com/us-9th-circuit/1097158.html

for the case of a Long-EZ builder who made major changes without notifying the FAA (as his OL's required) and the court ruled that his AC was not valid due to his not following the requirements of his OL's.

Will you get caught? Probably not. There are no "OL/AC" police, just as there are no "transponder 91.413 check" police, etc. But if you have insurance (per Mr. Davenport, above link) or if you get ramp checked, or..... and something happens, then there could be consequences. I try to get my customers to keep their aircraft as legal as can be, just in case.

Now, the LATEST version of Order 8130.2H (from which the OL's are derived) does allow for multiple configurations to be tested in Phase I, and if you do so and log it, you can go back and forth between tested configs without having to repeat Phase I. This is a good part of the lastest OL's, and if your original OL's require a new AC with a major change, you can request that the new OL's be written from this latest order.

Having said that, you may want to have new operating limitations issued so as to update to the latest version, since they are really much better than the ones that would have been issued in 1971. Give that some thought.

Absolutely so - see above.