Position updates

Position updates are sent every 5 seconds.

Pilots

Pilot position updates are prefixed with @:

@(mode):(callsign):(squawk):(rating):(lat):(lon):(alt):(groundspeed):(num1):(num2) 

Transponder mode

(mode) refers to the transponder mode. It consists of a single letter:

Mode Description
S Standby
N Mode C
Y Squawk ident

Regardless of transponder mode, the altitude is always included in a position update.

Squawk code

A squawk code of 7500 (aircraft hijacking) will result in an immediate disconnection from the server.

Unknown fields

The meaning of the following fields is unclear:

  • (num1) is a number of up to 10 digits. It seems to begin with 4.
  • (num2) is an integer. There seems to be a wide range of values, anywhere between 1 and 3 digits, and can be positive or negative.

ATC

ATC updates are prefixed with %:

%(callsign):(freq):(altitude):(protocol version):(rating):(lat):(lon)

ATC stations and observers also have a location and altitude associated with them, even though they do not move throughout a session.