I am at work right now and don't have the Service Bulletins manual, but I 
believe the factory recommended changing to the split elevator.

 

If so that will be approved data and possibly a minor alteration.  Also, the 
gross weight STC also references the split elevator:

 

 http://www.alpha-aviation.com/ERCOUPE%20STC.pdf

 

and at $200 for the STC would be cheaper than a DER approval and the other 
problems.

 

Bill


To: [email protected]; [email protected]
From: [email protected]
Date: Wed, 5 Aug 2009 07:53:14 -0500
Subject: RE: [ercoupe-tech] Conversion to Experimental Airworthiness Cert.

  





 

Thomas,

Start by saying that I’m not a mechanic of any kind, nor am I an A&P, AI nor 
expert in this subject.  These are my observations as an observer.

As I understand it, the FAA won’t allow a certificated airplane to be moved 
permanently into the experimental category.  Plus, the only category available 
to you would be Experimental Exhibition and you don’t want to go there.  I 
think you can forget this option.

The FAA seems to be only approving modifications approved by an FAA Designated 
Engineering Representative.  You have to spend money to have the DER do a full 
evaluation and write-up of your proposed mod.  That doesn’t guarantee the FAA 
will then permit the mod, but, if you pick a DER with a good relationship with 
the FAA it should fly.

The FAA may require you to put the plane in experimental status for a short 
time as you do flight testing on the modification.  I saw a Coupe with a 
3-blade composite prop at a national flyin a few years ago.  It had to go 
through the experimental flight test (and I think it required specific tests 
and records kept) phase before approval.
 
Does the Forney seat mod require any drilling in the spar?  At this moment, I 
don’t think the FAA will approve any spar drilling under any circumstances.

I’ll agree with Bill that moving the gascolator to the firewall is not an 
improvement.  I’ve never heard of a gascolator failing when the appropriate 
(easy to meet) ADs have been applied with the braces and, I think, brass 
fitting.  The factory mounting location eliminates low spots and high spots and 
makes for a pretty unlikely-to-fail installation.

The split elevator SHOULD be a no-brainer approval for the FAA.  The FAA did 
**extensive** testing of the configuration when it was certificated.  (Only God 
and *maybe* the FAA knows where those records are.)

The split elevator is an obviously better installation with no downside.  All 
it does is minimize trim changes when changing power, even from idle to full 
and visa versa.  It doesn’t change flying characteristics at all and only 
changes landing characteristics by returning planes with the 1320 pound STC (or 
D models) to the same landing speed as the 415-C.  (The split elevator is 
often, however, an expensive modification. I flew 800 hours with the 9° 
limitation and had no fuss.  This change never got near the top of my wish 
list.)

Again, this is a non-expert opinion.  It’s what I’ve seen and understood in 
trying to keep track of the modification process.

Ed








_________________________________________________________________
Windows Live™: Keep your life in sync.
http://windowslive.com/explore?ocid=PID23384::T:WLMTAGL:ON:WL:en-US:NF_BR_sync:082009

Reply via email to