Any change in hp or even engine model designation is considered to be a major change in the eyes of the FAA. One of my phase 1, 5 hr test periods was for a change from a C-85 to an O-200, a virtually identical engine. In your case, the testing was completed already with an O -235-C, so it should only require a log book entry and an updated W&B to change back. To the FAA, it would be like putting the original engine model back into a Cessna after having run out a higher hp engine that had been installed under an STC. That would require nothing more than a logbook entry and an uodate to the W&B.
-Jeff Scott -----Original message----- Sent: Saturday, 24 October 2015 at 22:14:59 From: "CraigW via KRnet" <krnet at list.krnet.org> To: KRnet <krnet at list.krnet.org> Subject: KR> major change or minor change Ok, its best to let the FSDO decide. Here is one that will cause some discussion. My Smith Miniplane was built with an O-235-C. At some point it was changed to an O-290-D. I am now putting in an O-235-C again. We are talking a 10 Hp change...Is this a major or minor change? Craig
