Definition
Civil Aviation Regulations (CAR) 3 was the airworthiness standard issued by the Civil Aeronautics Administration (and later the FAA) that governed the design and certification of small airplanes from the late 1940s until 1965. It set the structural, performance, flight characteristic, and equipment requirements an airplane had to meet to be certificated in the normal, utility, or acrobatic categories. CAR 3 was superseded by 14 CFR Part 23 in 1965, but many airplanes still flying today were originally certificated under CAR 3 and continue to be operated and maintained under those original standards.
Plain English
An older set of FAA design rules that small airplanes had to meet to be approved for use. It was replaced in 1965 by Part 23, but many older airplanes still in service today were built and certified under CAR 3.
Context Anchor
Pilots may see CAR 3 mentioned in older airplane manuals, type certificate data sheets, operating limitations, or discussions of an airplane’s certification basis.
Derivation
Civil' refers to non-military aviation. 'Regulation' comes from the Latin regula, meaning 'rule.' The '3' is simply the part number within the original Civil Aviation Regulations — Part 3 covered small airplane airworthiness, the same way Part 23 does today.
Why Pilots Care
Pilots of vintage aircraft must understand the original certification basis that still governs many aspects of their airplane's design and equipment requirements.
Analogy
Think of CAR 3 like an older building code. A house built under an older code may still be legal and safe to use, but you need to understand which rules applied when it was approved.
Intuition Check
CAR does not mean an automobile here. CAR 3 is not a vehicle, a checklist, or a flying procedure; it is an older set of government airworthiness rules for airplanes.
Example Sentence 1
The 1958 Piper Tri-Pacer was certificated under CAR 3, so its stall speed and load limits were established under the rules in effect at that time.
Example Sentence 2
Many older training airplanes still follow the CAR 3 standards for their basic airframe and systems.