Aircraft Radio Communication Systems

Radio communication with aircraft control is crucial for any aviator to safely and precisely navigate the skies. Because of this need, aircraft are fitted with radio equipment and a variety of antennas depending on their frequency band. Different aircraft require different antenna, with each having its own characteristics, applications, and location on the aircraft. This blog will explain the basics of aircraft antenna and a few of the radio communication systems in place today.

For short range communication, aircraft use the VHF (very high frequency) band which ranges from 118 MHz to 137 MHz. Communication ranges differ relative to the height of the antenna, meaning an aircraft at greater altitude would have a better VHF range than an aircraft at lower altitude. VHF range is the most important term in regards to radio communication capabilities. The formula to calculate the VHF range is as follows:

1.33 x (√H-Aircraft + √H-gs)

In this formula, H-aircraft represents the current altitude of the aircraft while H-gs represents the height of the ground station antenna in contact with the aircraft. This equation will give you the optimum range in perfect conditions, but the range is, of course, subject to atmospheric conditions as well as deficiencies in transmitter power, receiver sensitivity, and overall antenna performance. For a more realistic range, substitute 1.2 into the beginning of the formula.

VHF, in most cases, is suitable only for line of sight range, meaning it is not used for long range communications. In simpler terms, this means that the VHF band does not reach beyond the curvature of the earth. The high frequency (HF) band, from 3-30 MHz, is used for more reliable communication. Modern aircraft are equipped with separate radios and antenna specifically for long range communication.

At ASAP Aviation Procurement, owned and operated by ASAP Semiconductor, we can help you find all the unique radio communications parts for the aerospace, civil aviation, and defense industries. We’re always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, email us at or call us at 1-714-705-4780.


September 1, 2022