Definition
An aircraft certificated by the FAA in the Experimental category under the Amateur-Built airworthiness rules, where the major portion of the aircraft was fabricated and assembled by a person or persons for their own education or recreation. These aircraft are issued a special airworthiness certificate and operate under specific FAA-imposed operating limitations rather than the standard rules that apply to type-certificated aircraft.
Plain English
An aircraft built mostly by an individual (often from a kit or plans) for their own learning or enjoyment, then certified by the FAA under a special set of rules instead of the normal factory-built rules.
Context Anchor
Seen when comparing types of light-sport aircraft, checking an aircraft’s paperwork, or deciding what rules apply before flying a non-standard or homebuilt airplane.
Derivation
"Experimental" here is an FAA airworthiness category name, not a description of the aircraft's reliability. "Amateur-Built" refers to who built it, not its quality — "amateur" comes from the Latin amator, meaning one who does something for love rather than profession.
Why Pilots Care
It lets pilots build and fly their own aircraft at lower cost while accepting specific operating limitations on passengers, instruction, and commercial use.
Intuition Check
Do not read “experimental” as meaning the airplane is automatically unsafe or only used for testing. Here it means the aircraft is certificated under FAA experimental rules. Do not read “amateur-built” as meaning careless or low-quality; it means the major portion was built by non-manufacturers for education or recreation.
Example Sentence 1
Before flying his friend's RV-7, the pilot checked the airworthiness certificate and confirmed it was registered as an Experimental Amateur-Built aircraft, then reviewed its operating limitations.
Example Sentence 2
Many pilots select an Experimental Amateur-Built aircraft because it costs less than a factory-built plane while still meeting light-sport standards.