Bearings; radials; miles

This regulation establishes the standard references used throughout Part 73, which defines special use airspace like restricted areas, prohibited areas, and warning areas.

All bearings and radials referenced in Part 73 are measured as true bearings from their point of origin, not magnetic. This is important because you'll need to apply magnetic variation to use these bearings with your magnetic compass or heading indicator. For example, if a restricted area is described as extending along the 090° radial from a VOR, that's 090° true from that station.

Unless a specific description states otherwise, distances are given in statute miles (5,280 feet), not nautical miles (6,076 feet). This differs from most aviation operations where nautical miles are standard, so pay attention when calculating whether you're entering special use airspace. The difference between statute and nautical miles can be significant—10 statute miles equals only about 8.7 nautical miles.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*