Tap any paragraph to write a margin note. Your notes collect in the Desk below the text and file under cases with @. The side-by-side margin rail opens on a larger screen.

Code · CFR · Title 14 — Aeronautics and Space · Part 21 — Certification Procedures for Products and Articles · § 21.191

§ 21.191. Issue of experimental airworthiness certificates.

522 words·~2 min read·/us/cfr/t14/s§ 21.191·

A research copy — for the controlling text, always check the official state or federal source. Not legal advice.

Link to an amendment published at 90 FR 35207, July 24, 2025. Experimental airworthiness certificates are issued for the following experimental purposes:
(a)Research and development. Testing new aircraft design concepts, new aircraft equipment, new aircraft installations, new aircraft operating techniques, or new uses for aircraft.
(b)Showing compliance with regulations. Conducting flight tests and other operations to show compliance with the airworthiness regulations including flights to show compliance for issuance of type and supplemental type certificates, flights to substantiate major design changes, and flights to show compliance with the function and reliability requirements of the regulations.
(c)Crew training. Training of the applicant's flight crews.
(d)Exhibition. Exhibiting the aircraft's flight capabilities, performance, or unusual characteristics at air shows, motion picture, television, and similar productions, and the maintenance of exhibition flight proficiency, including (for persons exhibiting aircraft) flying to and from such air shows and productions.
(e)Air racing. Participating in air races, including (for such participants) practicing for such air races and flying to and from racing events.
(f)Market surveys. Use of aircraft for purposes of conducting market surveys, sales demonstrations, and customer crew training only as provided in § 21.195.
(g)Operating amateur-built aircraft. Operating an aircraft the major portion of which has been fabricated and assembled by persons who undertook the construction project solely for their own education or recreation.
(h)Operating primary kit-built aircraft. Operating a primary category aircraft that meets the criteria of § 21.24(a)(1) that was assembled by a person from a kit manufactured by the holder of a production certificate for that kit, without the supervision and quality control of the production certificate holder under § 21.184(a).
(i)Operating light-sport aircraft. Operating a light-sport aircraft that—
(1)Has not been issued a U.S. or foreign airworthiness certificate and does not meet the provisions of § 103.1 of this chapter. An experimental airworthiness certificate will not be issued under this paragraph
(i)for these aircraft after January 31, 2008;
(2)Has been assembled—
(i)From an aircraft kit; and
(ii)In accordance with manufacturer's assembly instructions that meet an applicable consensus standard; and
(iii)An experimental airworthiness certificate will not be issued under this paragraph (i)(2) for these aircraft after October 22, 2025; or
(3)Has been previously issued a special airworthiness certificate in the light-sport category under § 21.190. An experimental airworthiness certificate will not be issued under this paragraph for these aircraft after October 22, 2025.
(j)[Reserved]
(k)Operating light-sport category kit-built aircraft. Operating an aircraft of a type that has been certificated under § 21.190 and assembled from an aircraft kit in accordance with manufacturer's assembly instructions that meet an applicable FAA-accepted consensus standard.
(l)Operating former light-sport category aircraft. Operating an aircraft that previously has been issued a special airworthiness certificate in the light-sport category under § 21.190. [Amdt. 21-21, 38 FR 6858, May 7, 1968, as amended by Amdt. 21-57, 49 FR 39651, Oct. 9, 1984; Amdt. 21-70, 57 FR 41369, Sept. 9, 1992; Amdt. 21-85, 69 FR 44862, July 27, 2004; Amdt. 21-85, 69 FR 53336, Sept. 1, 2004; Amdt. 21-109, 90 FR 35207, July 24, 2025]
Connections24 cite this
★   the supreme law of the land   ★
Don't Tread on Me
E Pluribus Unum — out of many, one

"If you don't know your rights, you don't have any."

Marginalia · a citizen's law index
A research desk, not legal advice. Always read the cited source before relying on a summary.
Questions or an issue? support@self-law.org
disclaimerMarginalia is a research index, not a law firm. Nothing on this site is legal, tax, or financial advice and no attorney–client relationship is formed by using it. Statutes, regulations, and case law change; summaries, search results, AI output, and member posts may be incomplete, out of date, or wrong. Any interpretation drawn from material on this site should be validated by a licensed attorney in your jurisdiction before you act on it.