FAR 71.7 — Bearings and Mileages
FAR 71.7 explains how bearings, radials, and distances are measured in Part 71 airspace designations — true bearings from origin and nautical miles.
FAR 71.7 sets the measurement conventions used throughout Part 71, which is the part of the regulations that designates airspace areas, airways, routes, and reporting points.
The rule is short but important for interpreting any airspace description in Part 71:
- All bearings and radials referenced in Part 71 are true (referenced to true north, not magnetic north).
- Bearings and radials are applied from the point of origin (for example, from the navaid or fix being described).
- All mileages stated in Part 71 are in nautical miles, not statute miles.
Why it matters operationally: when you read a Part 71 description of a Class B, C, D, or E airspace area, a Federal airway, or a reporting point, you need to know that the numbers describing it are true bearings and nautical miles. This keeps airspace boundaries unambiguous and consistent across charts and legal descriptions, even though pilots typically navigate using magnetic courses in flight.