4 / 20

Which are the radio frequency bands normally used for aeronautical radio communications?

  • A
    VHF and MF.
  • B
    LF and VHF.
  • C
    VHF and HF.
  • D
    UHF and VHF.

The band normally used for Aeronautical Mobile Service (AMS) voice communication is defined between 118.000 and 136.975 MHz.

The AMS refers to VHF and HF voice communication. The VHF propagation is practically straight-line propagation (similar to light waves). Therefore, the VHF propagation characteristics are ideal for short-distance terrestrial communication. When, due to shadowing (e.g. by a hill), VHF communication is not possible, it is still possible to communicate using the upper part of the HF band where the surface wave is of little use.

The lower part of the previously mentioned spectrum, from 108 to 117.975 MHz, is reserved for navigational aids such as VOR beacons, Automatic Terminal Information Service (ATIS), precision approach system (ILS/LAAS).

Channel spacing in the airband has been 25 kHz. However, increasing congestion has led to further subdivision into 8.33 kHz channels in the ICAO European region.

Frequency bandFrequenciesWave bandWave length
VLFVery Low Frequency3-30 kHzVery long100-10 km
LFLow Frequency30-300 kHzLong10-1 km
MFMedium Frequency300-3000 kHzMedium1 km-100 m
HFHigh Frequency3-30 MHzShort100-10 m
VHFVery High Frequency30-300 MHzShort10-1 m
UHFUltra High Frequency300-3000 MHzUltra short1 m-10 cm
SHFSuper High Frequency3-30 GHz (3000-30 000 MHz)Super short10-1 cm
EHFExtremely High Frequency30-300 GHzExtremely short1 cm-1 mm


Your Notes (not visible to others)



This question has appeared on the real examination, you can find the related countries below.

  • Austro Control
    3
  • United Kingdom
    3
Keyboard Shortcut Use Keyboard Shortcuts