Aircraft Spotting in the digital age

FREE Registration.

Join our Forum to use our free guides and help.


Individual aircraft are assigned a unique 24-bit address defined by the ICAO (International Civil Aviation Organization), often referred to as a Mode-S or Hex (hexadecimal) code.  This unique address can be transmitted by the aircraft’s transponder and/or interrogated by ground based radar.  Mode-S operates on the radio frequencies 1030/1090 Mhz.

Without suitable software, the message received by the Mode-S receiver will be of limited use to the aviation enthusiast who would prefer to know the aircraft type, registration and owner.  We need software to translate the hex code into something more interesting.

Three of the available Mode-S receivers use bespoke software.  The others typically use the PlanePlotter software from the COAA.

Receiver specific software is usually included with the price of the receiver.  AirNav Systems charges extra for it’s so-called 3-D option and offers a subscription based service to access its data sharing server. PlanePlotter is available for a relatively low cost licence fee or some receivers include a free Lite version.

Typically, all software will translate the received data into a recognisable aircraft and, when transmitted, plot its position on a map.  There is usually a database to store historical flight data and update the aircraft details.  There are usually many other features and it’s best to read through some of our Guides or, where available, try out the time-limited trial or demo versions.