I've seen two friends get bit by this problem in the last two months so I thought I'd post a warning to those of you looking at buying homebuilt aircraft.

An Experimental/Homebuilt aircraft requires two documents relating to it's airworthiness certificate. The first is the airworthiness certificate itself and the second is a letter from the FAA entitled "Experimental Operating Limitations." This second document is NOT the weights, speeds, engine limits and other data we normally think of as operating limits. It is a letter delineating the types of operations for which the aircraft may be used. For instance with a homebuilt, it will always include a restriction against carrying people or property for hire.

When the homebuilt is first completed, it gets a temporary airworthiness certificate and operating limitations that restrict the aircraft to a certain area during flight testing. After the flight testing is complete, the aircraft gets a permanent airworthiness certificate and a different operating limitations letter.

The aircraft is not airworthy without the operating limitations letter! The airworthiness certificate says right on the front that the airworthiness certificate is not valid unless accompanied by the operating limitations letter.

One of my friends looked at an RV-6 with the intent to purchase it . When we got there, the owner did not have the operating limitations letter and could not find it. I advised my friend to walk away from the deal, which he did. If anyone is looking at an RV for sale at Pecan Plantation (0TX1), pm me. There's more than one snake in that woodpile.

My other friend bought a Rans. When I looked at the airplane, we could not find the operating limitations letter. He is now getting the FAA records on the aircraft and searching for a copy of the operating limitations letter. I hope I'm wrong but I suspect he's in for a bureaucratic hassle.

Here is a link to the EAA webpage that discusses buying and selling homebuilt aircraft. Caveat Emptor - let the buyer beware!

This depends on the age of the homebuilt. When my Long EZ was initially inspected by the DAR, he issued the operating limits which allowed for the flight testing and then the general operation of the airplane upon completion with a log book entry. I was issued the temporary airworthiness certificate that day, and received the permanent a month or two later. A lot has changed since then because the FAA has moved to standardize the process including Operating Limits. As someone who also does condition inspections on Homebuilts, I treat every homebuilt as different and read the specific Operating Limits. Years ago, each DAR developed his/her own operating limits which was then reviewed and concurred on by the FSDO. Some DARs have issued Operating Limits which require the experimental airplane's annual condition inspection to be signed off by an A&P IA.

Ignorance is not bliss when it comes to homebuilt airplanes. Do your homework before buying one. Get someone involved who understands Experimental Homebuilts. Contact the local EAA chapter. Find a builder. Most A&Ps will want to treat it like a certified airplane which is a mistake. I tell people who ask me to forget everything you know about certified airplanes and start over again. The rules are different, and it starts with the Operating Limits.

Yep. It can be a mess. My original OL was based on an outdated standard with prohibited any flight over populated areas or congested airways (neither of which is defined). I didn't discover that until after the DAR left. At that point I had to deal with the FSDO.

And that took them two OL's before they got it right.

Whatever was issued by the FAA will be in the Aircraft Records from OKC.
A friendly FSDO should be able to retrieve the document in a couple minutes. Otherwise a records CD request for $10 will get it for you.

This concerns me. I have been flying for 7 years with the operating limitations that the DAR gave me. Have I been living in sin? Not only that, but my airworthiness certificate was issued by a MIDO, not a FSDO. I guess I need to check further...

It's a great point, one often overlooked on warbirds....the "operating limitations" govern. Some are easy ("practice area is the continental US"), others....not so much.


It's not just experimental homebuilts...any experimental has ops limitations....whether it be a conversion that was done for proof of concept, or marketing research, etc.....


It's a question I have asked when looking at an airplane for sale "could you send a copy of the operating limitations".....it's amazing how quickly the question is dodged.


"I'll only send them if you send me a deposit and a sales contract".....


ummm.....no.

Depends. Unless it says temporary based on initial flight test.
For the Spitfire MkXVIII we had, EXP. Exhibition, there was a designated area for initial flights, an hour requirement for those flights and a statement to be put in the log book with a pilots signature and Cert number. Then you're allowed to freely roam within 600 statute mlesof the home base of record. Submit a yearly list of airshows and trips outside of that which a notification by email or fax to the FSDO would be needed for a pop up trip. Not needing an approval, just notification. Those were written in 2009. The plane was sold in 2015.

A can-do DAR might be willing and able to help you out in the absence of the operating letter. When my Dad passed in 2004, he left a ratty Kitfox in the shed. I dragged it home and drew upon the support of my local EAA chapter for support and connections. I maintained contact with the local DAR, who insisted on a few systems updates and put me back into phase 1. At the end he wrote a new operating letter. Still, 15 years ago.

Manufacturing DAR's are controlled by the MIDO, not the FSDO. I don't know what the current practice is for experimental, but it makes sense that a MIDO would issue it.

All the STCs I did in years past, the MIDO would put the aircraft into Experimental status for the flight testing, then back into a standard airworthiness cert once we were done.

When I was at Cessna, our Experimental R&D or Show Compliance certificates operating limits had restrictions on who could fly in the airplane.

Once we flew in one to an engine manufacturer meeting. We rationalized that engineers were OK, to evaluate engine or systems operation or such, but it was good excuse to leave the purchasing guy behind.