Definition
An aircraft issued a special airworthiness certificate in the experimental category by the FAA, authorizing operation for specific limited purposes such as research and development, showing compliance with regulations, crew training, exhibition, air racing, market surveys, or operating amateur-built or kit-built aircraft. Experimental aircraft are subject to operating limitations that restrict where, how, and for what purpose they may be flown, and they may not be used for compensation or hire except in narrowly defined circumstances.
Plain English
An aircraft that has been certified by the FAA under a special category that lets it fly, but only under set restrictions and for specific approved reasons — most commonly home-built or kit-built aircraft, or aircraft being tested.
Context Anchor
Seen in aircraft certification, airworthiness documents, aircraft logbooks, and preflight paperwork checks.
Derivation
From Latin experimentum, meaning 'a trial' or 'a test.' The name reflects the category's original purpose: aircraft flown for testing or development rather than standard production use. Today the category covers a broader set of uses, but the 'still being proven' flavor of the word remains accurate — these aircraft have not met the full certification standards required of standard-category aircraft.
Why Pilots Care
Pilots must know the operating limitations attached to the certificate, which can restrict passenger carrying, commercial use, and maintenance requirements.
Intuition Check
Experimental does not automatically mean unsafe, homemade, or casual. Here it means the aircraft is flying under a specific FAA approval with specific limits, rather than under a standard airworthiness certificate.
Example Sentence 1
Before flying his friend in the experimental aircraft he built from a kit, he made sure she understood it did not meet standard airworthiness requirements.
Example Sentence 2
Before purchasing an experimental aircraft, a pilot reviews the certificate to confirm what kinds of operations are permitted.