FAA Flight Instructor Airplane (FIA)Navigation and AirspaceMedium
A pilot planning an IFR flight above FL180 wants to determine the usable reception range of an H (High Altitude) class VOR between 18,000 and 45,000 feet MSL. According to standard VOR service volumes, what is the usable range?
- A40 NM
- B130 NM
- C100 NM
- D25 NM
Show answer & explanationAnswer & explanation
Correct answer: B. 130 NM
Per AIM 1-1-8, an H (High Altitude) class VOR provides 130 NM usable range between 18,000 feet MSL and 45,000 feet MSL. Lower altitudes provide shorter usable ranges (40 NM below 14,500 ft, 100 NM between 14,500 and 18,000 ft).
Why the other options are wrong
- A. 40 NM applies to altitudes below 14,500 feet AGL for an H class VOR.
- C. 100 NM applies to the band between 14,500 and 18,000 feet, not above 18,000.
- D. 25 NM is the range for a T (Terminal) class VOR, not an H class VOR.
VOR Service Volumes
Standard service volumes (T, L, H) define the reliable reception range and altitude of a VOR facility.
- T (Terminal): 25 NM up to 12,000 ft AGL
- L (Low): 40 NM up to 18,000 ft AGL
- H (High): 40/100/130 NM depending on altitude band
Memory trick: 'High flyers get 130 miles of trust' — H class VOR = 130 NM up high