sensors Mode-S transponder

4003AD

ICAO 24-bit transponder address · allocated to United Kingdom

Hex
4003AD
Octal
20001655
Decimal
4,195,245
Country
GB
No current signal · last broadcast 13h ago
Flights observed
148
Distinct callsigns
18
Country
GB
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 4003AD.

Country allocation

The ICAO 24-bit address 4003AD 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 18 distinct

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 IWY513 SJU → EIS May 29, 21:45 UTCMay 29, 22:00 UTC15m
2026-05-29 IWY512 EIS → SJU May 29, 20:10 UTCMay 29, 20:30 UTC20m
2026-05-29 IWY511 SJU → EIS May 29, 17:30 UTCMay 29, 17:45 UTC15m
2026-05-29 IWY510 EIS → SJU May 29, 15:50 UTCMay 29, 16:10 UTC20m
2026-05-28 IWY511 SJU → EIS May 28, 18:00 UTCMay 28, 18:20 UTC20m
2026-05-28 IWY510 EIS → SJU May 28, 16:15 UTCMay 28, 16:35 UTC20m
2026-05-27 IWY513 SJU → EIS May 27, 21:35 UTCMay 27, 21:50 UTC15m
2026-05-27 IWY512 EIS → SJU May 27, 20:20 UTCMay 27, 20:30 UTC10m
2026-05-27 IWY411 SDQ → EIS May 27, 18:50 UTCMay 27, 19:05 UTC15m
2026-05-27 IWY410 EIS → SDQ May 27, 15:50 UTCMay 27, 16:25 UTC35m
2026-05-27 IWY509 SJU → EIS May 27, 14:40 UTCMay 27, 14:55 UTC15m
2026-05-27 IWY508 EIS → SJU May 27, 13:20 UTCMay 27, 13:40 UTC20m
2026-05-26 IWY511 SJU → EIS May 26, 17:44 UTCMay 26, 17:59 UTC15m
2026-05-26 IWY510 EIS → SJU May 26, 16:10 UTCMay 26, 16:35 UTC25m
2026-05-25 IWY511 SJU → EIS May 25, 17:30 UTCMay 25, 17:50 UTC20m
2026-05-25 IWY510 EIS → SJU May 25, 15:50 UTCMay 25, 16:10 UTC20m
2026-05-25 IWY509 SJU → EIS May 25, 14:40 UTCMay 25, 15:00 UTC20m
2026-05-25 IWY644 SKB → SJU May 25, 13:05 UTCMay 25, 13:30 UTC25m
2026-05-24 IWY512 EIS → SJU May 24, 20:35 UTCMay 24, 20:55 UTC20m
2026-05-24 IWY511 SJU → EIS May 24, 17:45 UTCMay 24, 18:00 UTC15m
2026-05-24 IWY510 EIS → SJU May 24, 15:50 UTCMay 24, 16:05 UTC15m
2026-05-24 IWY509 SJU → EIS May 24, 14:35 UTCMay 24, 14:55 UTC20m
2026-05-24 IWY508 EIS → SJU May 24, 13:05 UTCMay 24, 13:25 UTC20m
2026-05-23 IWY511 SJU → EIS May 23, 17:45 UTCMay 23, 18:00 UTC15m
2026-05-23 IWY510 EIS → SJU May 23, 16:15 UTCMay 23, 16:35 UTC20m
2026-05-23 IWY509 SJU → EIS May 23, 14:50 UTCMay 23, 15:05 UTC15m
2026-05-23 IWY508 EIS → SJU May 23, 13:15 UTCMay 23, 13:35 UTC20m
2026-05-22 IWY513 SJU → EIS May 22, 21:45 UTCMay 22, 22:05 UTC20m
2026-05-22 IWY512 EIS → SJU May 22, 19:55 UTCMay 22, 20:15 UTC20m
2026-05-22 IWY511 SJU → EIS May 22, 18:15 UTCMay 22, 18:30 UTC15m
2026-05-22 IWY510 EIS → SJU May 22, 16:10 UTCMay 22, 16:30 UTC20m
2026-05-22 IWY509 SJU → EIS May 22, 14:50 UTCMay 22, 15:10 UTC20m
2026-05-22 IWY644 SKB → SJU May 22, 13:10 UTCMay 22, 13:35 UTC25m
2026-05-21 IWY643 SJU → SKB May 21, 21:25 UTCMay 21, 21:45 UTC20m
2026-05-21 IWY512 EIS → SJU May 21, 20:00 UTCMay 21, 20:20 UTC20m
2026-05-21 IWY511 SJU → EIS May 21, 17:45 UTCMay 21, 18:00 UTC15m
2026-05-21 IWY510 EIS → SJU May 21, 15:55 UTCMay 21, 16:15 UTC20m
2026-05-21 IWY509 SJU → EIS May 21, 14:30 UTCMay 21, 14:50 UTC20m
2026-05-21 IWY508 EIS → SJU May 21, 13:10 UTCMay 21, 13:25 UTC15m
2026-05-20 IWY511 SJU → EIS May 20, 17:20 UTCMay 20, 17:35 UTC15m
2026-05-20 IWY510 EIS → SJU May 20, 15:50 UTCMay 20, 16:10 UTC20m
2026-05-20 IWY509 SJU → EIS May 20, 14:30 UTCMay 20, 14:50 UTC20m
2026-05-20 IWY508 EIS → SJU May 20, 13:10 UTCMay 20, 13:25 UTC15m
2026-05-19 IWY513 SJU → EIS May 19, 21:40 UTCMay 19, 21:55 UTC15m
2026-05-19 IWY512 EIS → SJU May 19, 20:20 UTCMay 19, 20:40 UTC20m
2026-05-19 IWY411 SDQ → EIS May 19, 19:00 UTCMay 19, 19:25 UTC25m
2026-05-18 IWY410 EIS → SDQ May 18, 16:00 UTCMay 18, 16:35 UTC35m
2026-05-18 IWY509 SJU → EIS May 18, 14:40 UTCMay 18, 15:00 UTC20m
2026-05-18 IWY644 SKB → SJU May 18, 13:10 UTCMay 18, 13:35 UTC25m
2026-05-17 IWY643 SJU → SKB May 17, 21:45 UTCMay 17, 22:10 UTC25m

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.

Mode-S 4003AD frequently asked

What is Mode-S code 4003AD?
4003AD is an ICAO 24-bit transponder address. Allocated to United Kingdom.
Where is Mode-S 4003AD registered?
Mode-S code 4003AD 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 4003AD broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4003AD, octal 20001655, decimal 4,195,245.
What flights does 4003AD operate?
Mode-S 4003AD has broadcast 18 distinct callsigns, including IWY510, IWY511, IWY512, IWY509, IWY513.