Definition
A set of Federal Aviation Regulations (14 CFR Part 77) that establish standards for determining whether objects on or near an airport are obstructions to air navigation. Part 77 defines imaginary surfaces in the airspace around runways — such as the primary, approach, transitional, horizontal, and conical surfaces — and any object that penetrates these surfaces is considered an obstruction and may require evaluation, marking, lighting, or removal.
Plain English
A federal rulebook that draws invisible protective shapes in the sky around airports. Anything tall enough to poke into those shapes — a building, tower, tree, or crane — is officially treated as an obstruction and must be reviewed.
Context Anchor
You may see this term in instrument approach discussions, especially when the FAA is explaining whether obstacles near an airport allow a certain approach design or require higher landing limits.
Derivation
Named after Part 77 of Title 14 of the Code of Federal Regulations — the section number where these airspace rules live. The shorthand 'Part 77' is how pilots and planners refer to the whole regulation.
Why Pilots Care
These standards directly determine the protected airspace surfaces used to ensure safe obstacle clearance on RNAV and other instrument approaches.
Intuition Check
Do not read “Part 77 standards” as aircraft parts or general best practices. Here it means a specific FAA rule used to evaluate obstacles in airspace.
Example Sentence 1
The proposed crane near the runway was reviewed against Part 77 standards to see if it would penetrate the approach surface.
Example Sentence 2
Before approving the WAAS approach, the airport verified that all structures complied with Part 77 standards.