Does anyone have or know of a Piper J-4A on wheels with a field approved C-85 engine? I'm looking for a 337 form that has coverd this conversion. They are approved for seaplane in the J4 type certificate, but not for landplane.
Does anyone have or know of a Piper J-4A on wheels with a field approved C-85 engine? I'm looking for a 337 form that has coverd this conversion. They are approved for seaplane in the J4 type certificate, but not for landplane.
Post this over on j3-cub.com. There are a few guys that have j4s there. Also you could try the cub club. www.cub-club.com
Keith
This is how I found the pre Oct. 1955 Field Approvals that are considered approved data when I did my Vagabond. Go to www.landings.com and search for all J-4's. It will show what engine is installed. Write down N-number and serial number of every one with a C85. Go to www.faa.gov and request the records CD for each at a $10.00 price per CD. A week later you get the CD's in the mail, look for a 337 dated prior to October 1, 1955. It should also carry a CAA stamp. Get with your IA or FAA inspector and use that 337 as approved data for your Field Approval. Not really hard, just takes a little time.
Dave
Last edited by D.grimm; 02-29-2012 at 10:10 AM.
Just be warned about the belief that pre-1955 337's are automatically recognized by the FAA as approved data. I tried to use a pre-1955 337 when installing PA-12 wings on my Piper J5A. The FAA would not recognize as approved data a 337 I found using the process outlined in the previous post. Even after I gave them a photocopy of a letter on Piper letterhead from Piper's chief Engineer that PA-12 and J5A wings were interchangeable, the FAA still would not approve it. I needed to obtain a one-time STC for the alteration. It was alot of work and took nearly 3 years. Your best chance might be to find a good powerplant DER to go through the paperwork hassle. Good luck!
-Joel Marketello
I looked up the Aircraft Specification A-703 and I do not see where the C-85 is not allowed on a J4(A) land plane.
The C-85-12 is allowed as an optional engine per item 301(b) (4). I can not find any reference to just being approved on a seaplane. It appears to me all one needs to do is install the engine and make a make a log entry and revise weight and balance and equipment list. No 337 required as this is a minor alteration because it is listed in the A/C Specs. as an option.
I agree. According to the TCDS the C-85-12 is listed as one of the engines approved on the J-4A.
The regulations say that they may be used as aproved data. I wonder if the problem is at a certain FSDO in Texas. I've heard some horror stories out of that office including grounding an airplane that had a later model of the engine that came in it that had been approved by the Atlanta FSDO 12 years previously. The inspector said the Atlanta FSDO made a mistake and you better not fly that airplane, when shown the approval paperwork.
(OP) My problem is that I am taking a C-85 from a Cessna 140 including the mufflers and metal propeller & if possible would like to get a field approval (337) on the swap. The metal propeller isn't approved for a J4 w a C-85.
In so doing I have also replaced the Bendix carburetor with a Marvel Schebler unit to handle the J4A's cowl tank's low head pressure. I now understand that Al Ziebell at Oshkosh has done a number if J4 rebuilds. Unfortunately he died last October.
THX for the inputs guys!
Last edited by nrpetersen; 03-02-2012 at 01:51 PM.
There are numerous "one-time STC's" to put a C-85 in my Vagabond but my local FSDO won't allow that change now. They suggested I hang an A-65 (an STC is available for that) and then they could approve upgrade to a C-85. From what I've experienced, changes are mostly an exercise in patience with a system that needs more familiarity with older aircraft. Wish we could at least "shop" FSDO's.Originally Posted by D.grimm
Last edited by prasmussen; 04-30-2012 at 06:09 AM. Reason: typo
Update on my J4A - The local GADO office has been cooperative but it turns out there is a nasty AD on the Hanlon Wilson mufflers that I was planning to use. AD calls for 25 hr inspections for cracks - and no one is permitted to fix them. I decided to bite the bullet & now installing a C120/140/150 muffler system. Trouble is the nose bowl has some interferences so it is chop time to my cowl. But the muffler system is a much better package & I don't regret having to do it. The IA said that OK City FAA engineering would be very leary of any engine swap schemes that used that old muffler scheme.
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