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ACRO E-mail Archive Thread: [IAC-L:1862] Re: AD's om Exp A/C was MT3 Prop AD

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ACRO E-mail Archive Thread: [IAC-L:1862] Re: AD's om Exp A/C was MT3 Prop AD


Thread: [IAC-L:1862] Re: AD's om Exp A/C was MT3 Prop AD

Message: [IAC-L:1862] Re: AD's om Exp A/C was MT3 Prop AD

Follow-Up To: ACRO Email list (for List Members only)

From: Don Peterson <autotech at>

Date: Fri, 14 Nov 1997 04:04:20 UTC


 Steve Pennypacker wrote:
> How about certified engines/props on Experimental aircraft, *if* you ever
> have a desire to put the engine back on a certified aircraft at some later
> date, or merely want to keep it certified?
> >

Again, it is a "legal" point.  Once a certificated engine is put into an experimental 
aircraft, my FAA contacts tell me that it is no longer eligible to be put into a 
standard aircraft without an inspection.  Read this as "overhaul" (which is really just 
an inspection).  You can do all the stuff called out against its type certificate, but 
it buys you absolutely nothing other than peace of mind, and maybe a higher resale 
value.  The point of assigning a 25 hr fly-off instead of 40 hrs is because the 
engine/prop are a known entity WHEN INSTALLED.  You are not required to fly off 
additional time just because you elect to ignore an AD and continue flying with the 
wrong oil pump, or injector line brackets, etc.

This is not to say you couldn't yank out a 180HP engine out of a Pitts that has been 
operating at 3,700 RPM and drop it back into the Piper that it came out of, and pencil 
whip the logs.  The thing that makes it illegal (and a bad idea) is that the engine was 
operated in an aircraft, and in a manner, outside of its original certification 

Don Peterson


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