Definition
The section of the Federal Aviation Regulations that sets the airworthiness standards for manned free balloons, covering design, construction, and performance requirements that a balloon must meet to receive an FAA type certificate.
Plain English
A specific set of FAA rules that says what a manned balloon must be built like and able to do before the FAA will approve it as safe to fly.
Context Anchor
Seen in aircraft certification and airworthiness discussions, especially when comparing the rules for different kinds of aircraft.
Derivation
CFR stands for Code of Federal Regulations, the official collection of rules issued by U.S. federal agencies. Title 14 contains all aviation rules, and 'part 31' is one numbered chapter within that title. Knowing this helps a pilot read citations like '14 CFR part 31' as simply 'Title 14, Part 31 of the federal rulebook.'
Why Pilots Care
Balloon pilots and operators rely on these standards to confirm their aircraft is legally airworthy and safe to fly under FAA rules.
Intuition Check
Do not read “part” as a physical piece of an aircraft. Here, “part” means a numbered section of the federal aviation rules.
Example Sentence 1
The balloon manufacturer designed the envelope and burner system to meet the airworthiness standards in 14 CFR part 31.
Example Sentence 2
Before purchasing a used balloon, the pilot checked that it had been maintained in accordance with 14 CFR Part 31.