Last year at EAA Airventure I saw a helicopter (can't remember the model, but it was something like a Eurocopter EC135 or similar with a full glass cockpit). It was US registered (N-Number tail) but had "Experimental" written on the door.

When I asked the person at the booth why it was experimental they said it was because they used it as a test platform for new avionics packages, which got me thinking...

Is there a method to transition an aircraft from certified to experimental? Or is this done on a case-by-case basis through the FAA?

I can see advantages for an aircraft owner to want to transition to experimental if they want to keep up on latest (cheapest) non-TSO'd avionics and be able to do more work on the aircraft without an A&P. The downside is obviously higher insurance rates, but I'm not sure it would be a significant difference...


3 Answers 3


You essentially convert it to Experimental Exhibition, not Experimental Amateur-Built. That means more restrictions, depending on the FSDO. For instance, your operating limitations may prohibit passengers, or require permission for every flight over a given distance.

It is said that the FAA can be sensitive to people trying to put type-certificated aircraft into Experimental category for recreational use. Important advice below is that you should get permission from the FSDO before starting work on the airplane.

Even if you do this (and they likely won't like you converting say a Cherokee or a Cessna 172 to experimental), they will place certain restrictions on use, such as only flying within a 25 mile radius, and every year you may have to submit a "Program Letter" with a list of all the fly-ins and shows you are going to go to (since it is experimental-exhibition category, so you need to exhibit it!)

All that is to say, you probably will have a hard time converting a certificated plane to experimental and using it like it seems you intend to from your question.

Here is the relevant section from FAA Order 8130.2H.

Section 10. Certification and Operation of Aircraft Under the Experimental Purpose of Exhibition or Air Racing

  1. General. Under the provisions of § 21.191(d), exhibition aircraft are defined as aircraft that exhibit the aircraft’s flight capabilities, performance, or unusual characteristics at air shows, fly-ins, and aviation events; for motion picture, television, and similar productions; and for the maintenance of exhibition flight proficiency, including (for persons exhibiting aircraft) flying to and from such events and productions. Under the provisions of § 21.191(e), air racing aircraft are defined as aircraft that participate in air races, including (for such participants) practicing for such air races and flying to and from racing events.

a. Exhibition. A certificate for experimental exhibition must only be issued when an aircraft is to be used for valid exhibition purposes. Included in those purposes are organized air shows, organized fly-in activities, organized exhibitions, youth education events, organized aerobatic competition, fly-ins or meets, and movie or television productions. The duration of an airworthiness certificate for exhibition may be unlimited.

Here is an example of how to do it I found on a old page from the Robinson V8 Seabee Company website. (I found the page in the internet cache, so it is likely this method isn't foolproof)


Submit bill of sale for project Aircraft as "bought for salvage Parts" to the FAA. Add a separate letter of salvage in order to remove it from the FAA registry as Salvaged. This de-registers this A/C and is an important first step.


Obtain written permission from your local FAA Flight Standards District Office (FSDO) inspector in order to remove the data tag from the salvaged project aircraft. This step represents a great opportunity to develop a positive relationship with the FSDO inspector with whom you'll be working to complete the process. Be straightforward and explain that you require his help in order to certify your project in accordance with 14 CFR § 21.193, under a Special Airworthiness Certificate for the purposes of operating an aircraft in the experimental exhibition group 2 - Piston Engine Aircraft category, for the purposes of:

Demonstrating flight proficiency; Demonstrating the superior engine reliability of modern V8 engines; and Participating in exhibition of the aircraft at airshows and public event in order to educate the public about the unique and interesting characteristics of this aircraft

It is important to understand that the FAA FSDO inspectors are busy folks, and that they will appreciate the fact that you've done your homework. Maintain professionalism and don't expect an answer on the spot, as these inspectors have a number of strict procedures and guidelines within which they must work to accomplish the goal of certifying your aircraft. They deal with a great variety of aircraft and requests and may require some time to get up to speed on your specific request and understand the nature of your Robinson V8 aircraft.


Reserve a new N number on the FAA web site.

When your new N-number is confirmed by the FAA, simply submit forms 8050-88 and 8050-1 for the new N number as:

Manufacturer (preferably your new LLC Company or yourself). It cannot be the old manufacturer of the salvaged parts. Model (Example: Military Seabee OA-15) or whatever you want to call it. It cannot be the old model of the salvaged parts.

These forms need to be sent to the FAA Oklahoma City Registration Branch.

When your project is completed and ready for airworthiness inspection and operating limitations, issue a program letter to your FSDO inspector. With FAA application for airworthiness form 8130.6. They will take it from there.

Here is an example of program letter:

Program Letter Nxxxx

Date: May xx, 20xx

To: Mr. FAA Inspector

Federal Aviation Administration

XXXXX Flight Standards District Office

1234 Maple Lane

anytown, state zipcode

In accordance with 14 CFR § 21.193, I request a Special Airworthiness Certificate for my aircraft Nxxxx for the purpose of operating an experimental exhibition, group 2 - Piston Engine Aircraft. 1) For purposes of demonstrating flight proficency. 2) To demonstrate the superior engine reliability of modern V8 Engines. 3) To participate in exhibition of the aircraft at airshows and public events to educate the public about the unique and interesting characteristics of this aircraft.

The aircraft description is as follows:

Manufacturer: Your LLC Registration No.: Nxxxx

Model: Your model
Serial No.: xxxxx Engine Make/Model: Robinson LSV
No. of Engines: 01 Propeller Make/Model: xxxxx

Number of Seats: Four

The aircraft will be available for inspection at it’s base airport: (your airport and hangar location).

The aircraft will be weighed prior to flight to determine weight and balance data. The marking requirements of Part 45 will be complied with prior to flight, including permanent attachment of a fireproof identification (data) plate, permanent application of appropriate registration marks.

The following placards will be displayed in the cockpit in full view of all occupants:

The word “EXPERIMENTAL" displayed near the entrance to the cabin or cockpit; minimum 2 inches, maximum 6 inches in height.

"Passenger Warning – This Aircraft Does Not Comply With Federal Safety Regulations For Standard Aircraft" .

Instruments and system controls will be adequately marked, identified, and function properly prior to flight.

The power plant /propeller will be ground-run to sufficiently determine they are operating properly for flight.

The Aircraft will be maintained under an Annual condition inspection that meets the scope and detail of 14CFR part 43, Appendix D.

I request that airworthiness certification operating limitations be issued permitting me to operate the aircraft in phase one within 50 Nautical mile radius of (Your Base Airport) with the exception of all A,B,C and restricted airspace and avoiding flight over populated areas. Ten hours of phase one flight tests will be conducted to demonstrate control ability, engine reliability and establish the flight envelope. After Phase 1 flight test completion, I plan to operate the aircraft under Phase two operating limitations under VFR/day and VFR/night conditions under a group 2 Experimental Exhibition airworthiness certification within the continental U.S. proficiency area.

Kind Regards,


  • 1
    $\begingroup$ Jesus, Canuk, be grateful I don't know where your live cause, brother, if I did I'd be giving you a never ending bearhug of gratitude for that incredible answer! Not big on half-assing things, are ya?? 🤣 I'm the proud owner of a PA38-112 Piper Tomahawk which has the 125 HP upgrade. There literally isn't a more cost effective aircraft, new or used, which more closely matches my specific mission requirements than that little Rocket Sled! The problem is the erroneous ignorance-based stigmas attached to that model for the last 40 years has manifested today into ZERO AP options. I want to do this $\endgroup$
    – BigNutz
    Commented Nov 25, 2021 at 12:57

Canuk's answer provides a good summary of how a small piston aircraft might get an experimental airworthiness certification. This answer is intended to provide a more general view of what is needed.

FAA Order 8130.2 covers the topic of Airworthiness Certification of Products and Articles. Chapter 4 Section 7 covers general experimental airworthiness certifications.

For an aircraft to be eligible for an experimental certificate, the aircraft must be registered and the applicant must satisfy one or more of the purposes stated in 14 CFR 21.191, as discussed in chapter 4, sections 8 through 11 of this order.

These purposes are:

  1. LSA
  2. Amateur-Built
  3. Exhibition or Air Racing
  4. Research and Development, Showing Compliance With Regulations, Crew Training, Market Surveys, and Operating Kit-Built Aircraft

So if the aircraft will be used for one or more of those purposes, some paperwork and inspections will be required.

The FAA representative should become familiar with the aircraft type and its operational history, if any, before initiating the record and aircraft inspection.

FAA Form 8130-6 is required whenever an airworthiness certificate is issued or amended.

Experimental aircraft will also require a program letter.

The FAA uses the program letter to assist in establishing eligibility for an experimental certificate. The program letter must contain the required items listed in § 21.193 and be detailed enough to permit the FAA to prescribe the conditions and limitations necessary to ensure safe operation of the aircraft. Additional information and guidance concerning program letters can be found in appendix B to this order.

The required items listed include:

  • Purpose for which the aircraft is to be used
  • Unless converted from a previously type-certificated aircraft without significant change in the external configuration, the applicant must provide three-view drawings or three-view dimensioned photographs of the aircraft.
  • Any other pertinent information necessary to safeguard the general public.
  • For experimental purposes:
    • Purpose of the experiment to include the aircraft configuration or modifications, and outline the program objectives.
    • Estimated number of flights or total flight hours, and the period of time (for example, days or months), required for the experiment.
    • Areas over which the proposed flights are to be conducted.

LSA aircraft assembled from a kit or aircraft manufactured outside the United States have further requirements.

The aircraft must be registered and marked in accordance with part 47 and part 45, respectively.

For a small piston exhibition aircraft, there will also be a records inspection covering items including:

  • Necessary maintenance, inspection, operating, and flight manuals required to safely operate the aircraft.
  • Current maintenance records of inspections, overhauls, repairs, time-in-service
  • Maintenance and modification records for flight control balancing, fabricated parts, and supporting engineering documentation, if required
  • Appropriately rated FAA-certificated mechanic has made an entry in the aircraft records documenting the applicable inspections
  • Weight and balance data
  • Documentation about imported aircraft
  • Inspection program

Then there will be the aircraft inspection.

  • Verify instruments, instrument markings, and placards are as required by 14 CFR
  • Airspeed in knots, altimeters in feet, and distance measuring equipment in nautical miles
  • Flight control system operates properly
  • The engine(s), propeller(s), and associated instruments operate in accordance with the manufacturer’s instructions.
  • The pitot static system and associated instruments operate properly.

If all of this is in order, then the certificate may be issued.

  • $\begingroup$ Very detailed, thank you. I'd mark them both answer if it was possible... $\endgroup$
    – Ron Beyer
    Commented Jul 19, 2016 at 15:17

Yes there is a method. And to complicate things, there is more than one kind of Experimental certificates. Different types of certificates have different operating restrictions and bureaucratic overhead (e.g.; Experimental R&D requires annual renewal.) Details are available in the following FAA document:


  • 7
    $\begingroup$ Including the important information from the link would improve this answer. $\endgroup$
    – fooot
    Commented Jul 18, 2016 at 19:21
  • 1
    $\begingroup$ Even including the document identifier or similar (not just a URL) would improve this answer, because then people can get their hands on the document even if the provided URL itself becomes invalid for some reason. Compare Cool URIs don't change -- in real life, URIs change. A lot. $\endgroup$
    – user
    Commented Jul 18, 2016 at 21:51

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