Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

424B8B

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to M-AJOR · AIRBUS HELICOPTERS EC-145

Hex
424B8B
Octal
20445613
Decimal
4,344,715
Country
GB
Tail
M-AJOR
Type
EC45
No current signal · last broadcast 13d ago
Flights observed
86
Distinct callsigns
1
Country
GB
Last broadcast
13d ago

Last known position

Most recent position reported by Mode-S 424B8B.

Country allocation

The ICAO 24-bit address 424B8B falls within the block assigned to United Kingdom (GB) by ICAO Annex 10, Volume III. Every aircraft registered in United Kingdom receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 1 distinct

Callsign Airline Flights Last seen
MAJOR - 86 2026-06-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-30 MAJOR - Jun 30, 17:45 UTCJun 30, 18:15 UTC30m
2026-06-30 MAJOR - Jun 30, 17:15 UTCJun 30, 17:30 UTC15m
2026-06-30 MAJOR - Jun 30, 15:40 UTCJun 30, 15:55 UTC15m
2026-06-29 MAJOR - Jun 29, 13:54 UTCJun 29, 14:54 UTC1h 0m
2026-06-29 MAJOR - Jun 29, 13:19 UTCJun 29, 13:44 UTC25m
2026-06-26 MAJOR - Jun 26, 15:10 UTCJun 26, 15:45 UTC35m
2026-06-26 MAJOR - Jun 26, 14:39 UTCJun 26, 14:59 UTC20m
2026-06-26 MAJOR - Jun 26, 12:10 UTCJun 26, 12:24 UTC15m
2026-06-23 MAJOR - Jun 23, 15:50 UTCJun 23, 16:05 UTC15m
2026-06-23 MAJOR - Jun 23, 14:19 UTCJun 23, 14:35 UTC15m
2026-06-23 MAJOR - Jun 23, 13:45 UTCJun 23, 14:15 UTC30m
2026-06-19 MAJOR - Jun 19, 17:14 UTCJun 19, 17:34 UTC20m
2026-06-19 MAJOR - Jun 19, 16:59 UTCJun 19, 17:04 UTC5m
2026-06-19 MAJOR - Jun 19, 15:44 UTCJun 19, 15:59 UTC15m
2026-06-15 MAJOR - Jun 15, 11:45 UTCJun 15, 13:34 UTC1h 50m
2026-06-15 MAJOR - Jun 15, 09:15 UTCJun 15, 10:24 UTC1h 10m
2026-06-15 MAJOR CEQ → GNB Jun 15, 07:35 UTCJun 15, 08:40 UTC1h 5m
2026-06-14 MAJOR - Jun 14, 15:00 UTCJun 14, 15:15 UTC15m
2026-06-14 MAJOR - Jun 14, 14:40 UTCJun 14, 14:50 UTC10m
2026-06-14 MAJOR - Jun 14, 09:00 UTCJun 14, 09:15 UTC15m
2026-06-14 MAJOR - Jun 14, 08:35 UTCJun 14, 08:45 UTC10m
2026-06-13 MAJOR - Jun 13, 13:00 UTCJun 13, 13:15 UTC15m
2026-06-13 MAJOR - Jun 13, 12:40 UTCJun 13, 12:50 UTC10m
2026-06-13 MAJOR - Jun 13, 06:50 UTCJun 13, 07:30 UTC40m
2026-06-12 MAJOR - Jun 12, 16:15 UTCJun 12, 16:30 UTC15m
2026-06-12 MAJOR - Jun 12, 15:50 UTCJun 12, 16:05 UTC15m
2026-06-12 MAJOR - Jun 12, 09:05 UTCJun 12, 09:50 UTC45m
2026-06-10 MAJOR - Jun 10, 12:00 UTCJun 10, 13:35 UTC1h 35m
2026-06-10 MAJOR - Jun 10, 08:30 UTCJun 10, 10:10 UTC1h 40m
2026-06-05 MAJOR - Jun 5, 10:40 UTCJun 5, 11:05 UTC25m
2026-05-23 MAJOR - May 23, 09:40 UTCMay 23, 10:40 UTC1h 0m
2026-05-23 MAJOR - May 23, 08:45 UTCMay 23, 09:15 UTC30m
2026-05-21 MAJOR - May 21, 17:10 UTCMay 21, 17:25 UTC15m
2026-05-21 MAJOR - May 21, 16:15 UTCMay 21, 16:30 UTC15m
2026-05-21 MAJOR - May 21, 14:55 UTCMay 21, 15:25 UTC30m
2026-05-19 MAJOR - May 19, 19:10 UTCMay 19, 20:10 UTC1h 0m
2026-05-19 MAJOR - May 19, 15:55 UTCMay 19, 16:05 UTC10m
2026-05-19 MAJOR - May 19, 14:10 UTCMay 19, 14:55 UTC45m
2026-05-18 MAJOR - May 18, 16:45 UTCMay 18, 17:15 UTC30m
2026-05-18 MAJOR - May 18, 16:15 UTCMay 18, 16:30 UTC15m
2026-05-18 MAJOR - May 18, 15:05 UTCMay 18, 15:25 UTC20m
2026-05-18 MAJOR - May 18, 14:20 UTCMay 18, 14:50 UTC30m
2026-05-18 MAJOR - May 18, 13:45 UTCMay 18, 13:55 UTC10m
2026-05-17 MAJOR - May 17, 17:25 UTCMay 17, 17:55 UTC30m
2026-05-17 MAJOR - May 17, 15:50 UTCMay 17, 17:05 UTC1h 15m
2026-05-17 MAJOR - May 17, 08:30 UTCMay 17, 09:40 UTC1h 10m
2026-05-15 MAJOR - May 15, 14:15 UTCMay 15, 15:35 UTC1h 19m
2026-05-15 MAJOR - May 15, 13:15 UTCMay 15, 13:45 UTC30m
2026-05-14 MAJOR - May 14, 15:40 UTCMay 14, 16:10 UTC30m
2026-05-14 MAJOR - May 14, 15:10 UTCMay 14, 15:25 UTC15m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Prefer a tail-number view? See the M-AJOR page for operator, model, and routing details .

Mode-S 424B8B frequently asked

What is Mode-S code 424B8B?
424B8B is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to M-AJOR.
Where is Mode-S 424B8B registered?
Mode-S code 424B8B is allocated to United Kingdom (GB). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 424B8B broadcasting right now?
No active broadcast right now. Last signal was 13d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 424B8B, octal 20445613, decimal 4,344,715.
What flights does 424B8B operate?
Mode-S 424B8B has broadcast 1 distinct callsign, including MAJOR.