UK squawk code reference

A conditional fallback when no air traffic services code-setting instruction has been given.

SERA allows 2000, or another code prescribed by the competent authority, when there is no ATS instruction about which code to use. It is not a universal identity or mission label.

Used to improve detection when an aircraft is not receiving air traffic services, unless the competent authority prescribes otherwise.

This is a conditional conspicuity meaning. It does not identify the aircraft, operator, route or purpose of flight.

The SERA contingency code associated with unlawful interference.

This page states the published meaning only. It is not an instruction to change a transponder setting and must never replace current procedures or ATC instructions.

The SERA contingency code associated with radio-communication failure.

A displayed code is only one part of an operational situation. Do not use this reference to infer an aircraft's identity or the details of an event.

The SERA contingency code associated with a state of emergency.

The code alone does not explain the nature, severity or location of an emergency. Follow official operational information, not assumptions from a tracking display.

The UK CAA publishes 0030 for an aircraft that is lost.

This reference states the published UK meaning only. It is not a substitute for current procedures, ATC instructions or an emergency call when one is required.

Published for aircraft monitoring Aberdeen Radar on 119.055 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Aldergrove Approach on 133.130 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Belfast Approach on 130.855 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Birmingham Radar on 123.980 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Bournemouth Radar on 119.480 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Bristol Radar on 125.655 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Cardiff Approach on 119.155 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring East Midlands Radar on 134.180 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Edinburgh Radar on 121.205 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Farnborough Radar on 125.250 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Glasgow Radar on 119.105 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Hawarden Radar on 120.055 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Leeds Radar on 134.580 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Liverpool Radar on 119.855 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Liverpool Radar on 119.855 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Gatwick Director on 126.825 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Luton Radar on 129.550 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Stansted Radar on 120.625 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Manchester Radar on 118.580 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Manchester Radar on 118.580 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Newcastle Radar on 124.380 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Norwich Radar on 119.355 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Oxford Radar on 125.090 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Solent Radar on 120.230 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Southend Radar on 130.780 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Teesside Radar on 118.855 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Thames Director on 132.700 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Published for aircraft monitoring Warton Radar on 129.530 MHz without requesting an air traffic service.

This is a listening code, not an air traffic service. The pilot remains responsible for navigation and for staying outside controlled airspace unless cleared to enter.

Note 4: Ground based transponder equipment.

(Refer to ENR 1.6, paragraph 2.2.3)

Surrey/Sussex HEMS (HLE60)

Scottish Non-standard Flights

British Transport Police ASU

Note 9: This conspicuity code shall be used by aircraft operating in an Off-shore Safety Area (OSA) when contact with the Area Air Traffic Service Provider (ATSP) has not been established and no other code has previously been allocated.

This code may be used when flying in the vicinity of Birmingham, operating outside of Birmingham CTR/ Birmingham CTA and monitoring Birmingham Radar frequency within the area defined in EGBB AD 2.22 FLIGHT PROCEDURES.

(Refer to ENR 1.6, paragraph 2.2.5)

This code may be used when flying in the vicinity of Bournemouth Control Zone and monitoring Bournemouth Radar Frequency within the area defined in EGHH AD 2.22 FLIGHT PROCEDURES. The delineation with Solent is west of a line between Stoney Cross VRP and Hurst Castle VRP.

(Refer to ENR 1.6, paragraph 2.2.5)

This code may be used when flying in the vicinity of London City and London Heathrow and operating outside of the London CTR/London City CTR/London CTA but within the area defined in EGLC AD 2.22 FLIGHT PROCEDURES and EGLL AD 2.22 FLIGHT PROCEDURES.

(Refer to ENR 1.6, paragraph 2.2.5)

This code may be used when flying in the vicinity of London Luton and operating outside of the London Luton CTR/ London Luton CTA but within the area defined in EGGW AD 2.22 FLIGHT PROCEDURES.

(Refer to ENR 1.6, paragraph 2.2.5)

Kent Air Ambulance (HLE21)

Essex Air Ambulance (HLE07)

Thames Valley Air Ambulance (HLE24)

London Air Ambulance (HLE27)

Air Ambulance Helicopter Emergency Medivac

Fixed-wing aircraft (Receiving service from a ship)

Helicopter(s) (Receiving service from a ship)

Aircraft engaged in actual SAR Operations

Radar Flight Evaluation/Calibration

Aircraft conducting radar evaluation/calibration flights shall only squawk 0024 for the duration of the trial. The code shall not be used whilst transiting to/from the trial; in such circumstances the appropriate Mode A code as per paragraph 2.2.2.1 should be selected. May be selected at pilot's discretion. (Refer to ENR 1.6, paragraph 2.2.2.2)

Scottish Non-standard Flights

Special Tasks

London Control (Swanwick) Ops Crossing/Joining CAS

Note 7: This code is assigned by the FISO to aircraft requesting entry into Controlled Airspace for the purpose of joining or crossing the ATS Route network. Pilots shall only select the code when they are within two-way communication with the London FIS. Where available, the Mode C pressure-altitude reporting mode of the transponder should also be selected. If communication is lost or the aircraft leaves the FIS frequency, pilots shall deselect this special purpose code. The assignment of this code does not imply the provision of a radar service and the code and any associated Mode C pressure-altitude reporting data must be considered to be unvalidated and unverified.

FIR Lost

Hertfordshire Air Ambulance (HLE55)