Transponder (aeronautics)

Cessna ARC RT-359A transponder (beige box), beneath a VHF radio. In this example, the transponder code selected is 1200 for VFR flight (in North American airspace). The green IDENT button is marked "ID".

A transponder (short for transmitter-responder[1] and sometimes abbreviated to XPDR,[2] XPNDR,[3] TPDR[4] or TP[5]) is an electronic device that produces a response when it receives a radio-frequency interrogation. Aircraft have transponders to assist in identifying them on air traffic control radar. Collision avoidance systems have been developed to use transponder transmissions as a means of detecting aircraft at risk of colliding with each other.[6][7]

Air traffic control units use the term "squawk" when they are assigning an aircraft a transponder code, e.g., "Squawk 7421". Squawk thus can be said to mean "select transponder code" or "squawking xxxx" to mean "I have selected transponder code xxxx".[6]

The transponder receives interrogation from the Secondary Surveillance Radar on 1030 MHz and replies on 1090 MHz.

  1. ^ Mangine, Robert (2007). "The Truth About Transponders". Archived from the original on August 16, 2011. Retrieved March 5, 2019.
  2. ^ Farlex, Inc. (2008). "XPDR". Retrieved December 24, 2008.
  3. ^ Farlex, Inc. (2008). "XPNDR". Retrieved December 24, 2008.
  4. ^ Farlex, Inc. (2008). "TPDR". Retrieved December 24, 2008.
  5. ^ Farlex, Inc. (2008). "TP". Retrieved December 24, 2008.
  6. ^ a b Transport Canada (May 20, 2010). "TP 14371 — Transport Canada Aeronautical Information Manual (TC AIM) RAC 1.9 Transponder Operation". Archived from the original on July 9, 2010. Retrieved August 21, 2010.
  7. ^ Peppler, I. L. (1996). From The Ground Up (27th Revised ed.). Ottawa Ontario: Aviation Publishers. pp. 238–239. ISBN 0-9690054-9-0.

Developed by StudentB