Ask the DAR

Repairman certificate eligibility, ELSA mods, flying at civil twilight, fuel cap engraving. By Mel Asberry.


Question: I recently purchased an original design homebuilt airplane loosely based on a J-4 Cub with two-place side-by-side seating. The builder/designer obtained an N-number and flew off the 40 hours. At that point he decided to replace the 90-hp Continental engine with a new Corvair he assembled himself. He did not get the aircraft flying with the new engine.

I need to complete the engine installation, reinstall the wings, and do many other repairs to make the aircraft airworthy. I have not yet taken the course offered by Rainbow Aviation, but plan to do so very soon. Can I do this necessary work myself, make the logbook entries, and in the future do the annual condition inspections myself?

Answer: As I understand, your aircraft is certificated as an Experimental/Amateur-Built. It will remain an E/A-B throughout its life. It cannot be converted to a Light Sport Aircraft. Therefore the Rainbow Aviation course will be of no help in getting the repairman certificate for this aircraft. The only path to qualify for a repairman certificate for this aircraft is to be listed as a primary builder at the original certification of the aircraft.

Replacing the engine is considered a major change and would normally require a new Phase I flight test, but since the aircraft is still in the original Phase I period, that will not be necessary.

Anyone may perform maintenance, and even modifications, to an Experimental Amateur-Built aircraft, so you are good to go in that respect. However, you will not be able to perform the annual condition inspection. Only the original builder, if he has obtained the repairman certificate, or a certificated A&P mechanic may perform the condition inspection required by your operating limitations.

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Question: My ELSA RV-12 just passed its airworthiness inspection. Do I need to finish Phase 1 testing before I can make modifications?

Answer: No. An ELSA can be modified immediately after certification.

Question: I have a Private Pilot license and have let my 3rd-class medical expire; therefore, I exercise the privileges of a Sport Pilot. My aircraft is licensed as an E/A-B, and it meets the definition of a Light Sport Aircraft. I have been unable to get a definitive answer to this question: Does day VFR include civil twilight?

Answer: Thanks for your question. FAR Part 61.315(b)(5) states that you may not fly “at night” while exercising the privileges of a Sport Pilot. FAR Part 1.1 defines “night” as “the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time.” So, it looks to me like you are good to go during civil twilight.

Question: I plan to get my fuel caps engraved, but I’m not exactly sure what information is required. I’m pretty sure I need to include capacity and type of fuel, but is there anything else? Also, what happens when 100LL goes away? Should I have the wording on the caps say something like “100LL or Equivalent Octane”?

Answer: Only fuel tank capacity and minimum octane rating are required. Lead content has no bearing on this.

Please send your questions for DAR Asberry to with “Ask the DAR” in the subject line.

Mel Asberry is an experienced Designated Airworthiness Representative specializing in Experimental/Amateur-Built aircraft. He and his wife, Ann, have built seven amateur-built airplanes including two ultralight types, a Moni Motorglider, a Dragonfly Mk2, two RV-6s and a Zenair CH 601HDS. They are currently building a scratch-built biplane.


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