Definition
The section of the Federal Aviation Regulations governing the operation of ultralight vehicles in the United States. It defines what qualifies as an ultralight, where and when ultralights may be flown, and the operating limitations that apply. Ultralights operated under part 103 do not require pilot certification, aircraft registration, or airworthiness certificates.
Plain English
A specific set of FAA rules covering single-seat ultralight aircraft. If your aircraft fits the size, weight, and speed limits in these rules, you can fly it without a pilot license or aircraft registration, but you must follow the operating restrictions in this part.
Context Anchor
You may see 14 CFR part 103 when reading about ultralight operations, checking whether a small flying vehicle legally qualifies as an ultralight, or reviewing where ultralights may operate.
Derivation
CFR stands for Code of Federal Regulations, the official compilation of U.S. federal rules. Title 14 covers aeronautics and space. 'Part 103' is simply the chapter number within Title 14 that addresses ultralight vehicles. The numbering is administrative, not descriptive.
Why Pilots Care
It defines the legal boundaries for flying ultralights without needing a pilot certificate or aircraft registration in most cases.
Intuition Check
Do not read “part 103” as just a label for any very light aircraft. It is a specific set of FAA rules, and the vehicle and operation must meet those rules to qualify.
Example Sentence 1
The pilot's single-seat powered paraglider is operated under 14 CFR part 103, so no airman certificate or aircraft registration is required.
Example Sentence 2
14 CFR part 103 allows pilots to operate ultralights over unpopulated areas during daylight hours without filing a flight plan.