Definition
A radio-navigation reference distance of 100 nautical miles used in certain VOR (VHF Omnidirectional Range) accuracy and service-volume specifications. It defines the maximum reception range from a high-altitude VOR station within which signal accuracy and usability are guaranteed under standard conditions.
Plain English
A standard 100-nautical-mile distance used as a yardstick for how far away a pilot can reliably receive a navigation signal from a high-altitude VOR station.
Context Anchor
Seen in aviation regulations, weather discussions, training material, and distance limits where the exact kind of mile matters.
Derivation
Mile comes from the Latin idea of a thousand paces. That helps because a mile is a measured distance, but aviation uses more than one kind of mile, so the context matters.
Why Pilots Care
Determines whether a flight meets minimum distance requirements for certificates or stays inside allowed local training areas.
Intuition Check
Do not assume 100 Miles always means 100 nautical miles. If the source says only “miles,” check the context; visibility and many rules may use ordinary land miles, while navigation distances often say nautical miles or NM.
Example Sentence 1
The high-altitude VOR is rated for reliable reception out to 100 miles, so the pilot planned the cruise leg to stay within that range.
Example Sentence 2
We calculated the total route distance at 100 miles so the trip stayed within day VFR fuel and planning rules.