Victor airways
Victor airways are pre-determined routes flown by pilots under instrument flight rules (IFR). They are defined by VHF omnidirectional range (VOR) radials and have established minimum (and possibly maximum) altitudes at which they may be flown. Victor airways are depicted as black solid lines on IFR Low-Altitude Enroute charts and as thick faded blue lines on visual flight rules (VFR) Terminal and Sectional Area charts. They may be likened as "highways in the sky" and are identified by a number, similar to an interstate highway (for example, a pilot could say that he/she is "flying Victor Eight").
Victor airways are, by definition, surrounded by Class E airspace from 1,200 feet (370 m) above ground level (AGL) up to, but not including, 18,000 feet (5,500 m) above mean sea level (AMSL). These virtual airways are defined primarily by VORs, and comprise a system of established routes that run along specified VOR radials, hence the beginning letter V (see NATO Phonetic alphabet).
The width of the victor corridor depends on the distance from the navigational aids (such as VORs and non-directional beacons (NDBs):
- When VORs are less than 102 nautical miles (NM) (189 km) from each other, the Victor airway extends 4 NM (7.4 km) on either side of the center line (8 NM (14.8 km) total width).
- When VORs are more than 102 NM from each other, the width of the airway in the middle increases. The width of the airway beyond 51 NM from a navaid is 4.5 degrees on either side of the center line between the two navaids (at 51 NM from a navaid, 4.5 degrees from the centerline of a radial is equivalent to 4 NM). The maximum width of the airway is at the middle point between the two navaids. This is when 4.5 degrees from the center radial results in a maximum distance for both navigational aids.
