Definition
CAR 3 is a former United States airworthiness standard that governed the design and certification of small airplanes from 1945 until it was replaced by Part 23 of the Federal Aviation Regulations in 1965. Many older general aviation airplanes still flying today were originally certificated under CAR 3, and they continue to be operated and maintained according to the standards in effect at the time of their certification.
Plain English
CAR 3 is the old set of design rules that small airplanes had to meet to be legally built and sold in the U.S. before 1965. A lot of older airplanes still in service today were built under those rules, and they are still flown and maintained to that original standard.
Context Anchor
You may see CAR 3 mentioned when reading about older training airplanes, airplane certification, operating limitations, or the approval basis for an aircraft design.
Derivation
CAR stands for Civil Aviation Regulations, the rulebook published by the Civil Aeronautics Authority (and later the Civil Aeronautics Board) before the FAA was established. Part 3 of those regulations covered small airplanes. When the FAA reorganized the rules into the Federal Aviation Regulations in the 1960s, CAR 3 became the basis for what is now FAR Part 23.
Why Pilots Care
Many classic training and personal aircraft still in service were certified under CAR 3, so pilots must know which standards apply to their airplane's type certificate and operating limitations.
Analogy
Think of CAR 3 like an older building code. A building may still be legal and safe even though it was approved under an earlier code, but you need to understand which rules applied when it was approved.
Intuition Check
CAR 3 does not refer to an automobile, and the “3” is not a model number. It refers to an older aviation rule set used to approve certain airplane designs.
Example Sentence 1
The Cessna 172 in our flight school was originally certificated under CAR 3, so its required equipment list reflects those older standards.
Example Sentence 2
Before buying an older airplane, check whether its type certificate was issued under CAR 3 or Part 23.