Apparatus

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sensors Mode-S transponder

4015A4

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-ASAL · BRITISH AEROSPACE SA-3 Bulldog

Hex
4015A4
Octal
20012644
Decimal
4,199,844
Country
GB
Tail
G-ASAL
Type
BDOG
No current signal · last broadcast 4d ago
Flights observed
58
Distinct callsigns
1
Country
GB
Last broadcast
4d ago

Last known position

Most recent position reported by Mode-S 4015A4.

Country allocation

The ICAO 24-bit address 4015A4 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
GASAL - 58 2026-07-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-22 GASAL - Jul 22, 16:55 UTCJul 22, 17:35 UTC40m
2026-07-21 GASAL - Jul 21, 14:35 UTCJul 21, 15:05 UTC30m
2026-07-21 GASAL - Jul 21, 11:50 UTCJul 21, 12:10 UTC20m
2026-07-17 GASAL - Jul 17, 16:10 UTCJul 17, 16:44 UTC35m
2026-07-17 GASAL - Jul 17, 13:45 UTCJul 17, 14:10 UTC25m
2026-07-12 GASAL PIK → PIK Jul 12, 14:30 UTCJul 12, 15:30 UTC1h 0m
2026-07-12 GASAL - Jul 12, 08:15 UTCJul 12, 10:05 UTC1h 50m
2026-07-11 GASAL - Jul 11, 10:20 UTCJul 11, 10:40 UTC20m
2026-07-11 GASAL - Jul 11, 08:01 UTCJul 11, 09:50 UTC1h 50m
2026-07-10 GASAL - Jul 10, 15:05 UTCJul 10, 16:10 UTC1h 5m
2026-07-03 GASAL PIK → PIK Jul 3, 10:45 UTCJul 3, 10:55 UTC10m
2026-06-25 GASAL - Jun 25, 14:59 UTCJun 25, 15:10 UTC10m
2026-06-24 GASAL - Jun 24, 13:14 UTCJun 24, 14:00 UTC45m
2026-06-23 GASAL - Jun 23, 14:04 UTCJun 23, 14:59 UTC55m
2026-06-23 GASAL - Jun 23, 11:35 UTCJun 23, 11:49 UTC15m
2026-06-23 GASAL - Jun 23, 09:49 UTCJun 23, 10:24 UTC35m
2026-06-21 GASAL - Jun 21, 19:05 UTCJun 21, 19:39 UTC35m
2026-06-21 GASAL - Jun 21, 08:54 UTCJun 21, 09:10 UTC15m
2026-06-20 GASAL - Jun 20, 15:14 UTCJun 20, 16:19 UTC1h 5m
2026-06-19 GASAL - Jun 19, 15:44 UTCJun 19, 16:19 UTC35m
2026-06-19 GASAL - Jun 19, 13:59 UTCJun 19, 14:59 UTC1h 0m
2026-06-19 GASAL - Jun 19, 10:14 UTCJun 19, 11:20 UTC1h 5m
2026-06-18 GASAL - Jun 18, 20:15 UTCJun 18, 20:35 UTC20m
2026-06-18 GASAL - Jun 18, 11:50 UTCJun 18, 12:05 UTC15m
2026-06-18 GASAL - Jun 18, 09:25 UTCJun 18, 09:40 UTC15m
2026-06-16 GASAL - Jun 16, 17:45 UTCJun 16, 18:05 UTC20m
2026-06-16 GASAL - Jun 16, 15:35 UTCJun 16, 16:00 UTC25m
2026-06-16 GASAL - Jun 16, 09:10 UTCJun 16, 09:34 UTC25m
2026-06-15 GASAL - Jun 15, 14:10 UTCJun 15, 15:15 UTC1h 5m
2026-06-15 GASAL - Jun 15, 10:05 UTCJun 15, 11:54 UTC1h 50m
2026-06-14 GASAL - Jun 14, 15:50 UTCJun 14, 16:55 UTC1h 5m
2026-06-14 GASAL - Jun 14, 13:30 UTCJun 14, 14:15 UTC45m
2026-06-14 GASAL - Jun 14, 11:45 UTCJun 14, 12:10 UTC25m
2026-06-14 GASAL - Jun 14, 08:45 UTCJun 14, 09:10 UTC25m
2026-06-06 GASAL - Jun 6, 11:05 UTCJun 6, 11:19 UTC15m
2026-05-31 GASAL - May 31, 12:45 UTCMay 31, 14:20 UTC1h 35m
2026-05-27 GASAL - May 27, 13:05 UTCMay 27, 14:15 UTC1h 10m
2026-05-25 GASAL - May 25, 15:45 UTCMay 25, 16:10 UTC25m
2026-05-25 GASAL PIK → PIK May 25, 14:00 UTCMay 25, 15:10 UTC1h 10m
2026-05-25 GASAL PSL → PIK May 25, 12:05 UTCMay 25, 13:05 UTC1h 0m
2026-05-25 GASAL - May 25, 08:50 UTCMay 25, 10:00 UTC1h 10m
2026-05-16 GASAL - May 16, 12:01 UTCMay 16, 12:35 UTC35m
2026-05-16 GASAL - May 16, 09:25 UTCMay 16, 09:40 UTC15m
2026-05-14 GASAL - May 14, 10:20 UTCMay 14, 11:01 UTC40m
2026-05-11 GASAL - May 11, 16:55 UTCMay 11, 17:30 UTC36m
2026-05-09 GASAL - May 9, 13:00 UTCMay 9, 13:15 UTC15m
2026-05-08 GASAL - May 8, 12:49 UTCMay 8, 13:40 UTC50m
2026-05-06 GASAL - May 6, 12:10 UTCMay 6, 12:35 UTC25m
2026-05-04 GASAL - May 4, 09:20 UTCMay 4, 10:00 UTC40m
2026-05-04 GASAL - May 4, 07:45 UTCMay 4, 08:20 UTC35m

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 G-ASAL page for operator, model, and routing details .

Mode-S 4015A4 frequently asked

What is Mode-S code 4015A4?
4015A4 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-ASAL.
Where is Mode-S 4015A4 registered?
Mode-S code 4015A4 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 4015A4 broadcasting right now?
No active broadcast right now. Last signal was 4d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4015A4, octal 20012644, decimal 4,199,844.
What flights does 4015A4 operate?
Mode-S 4015A4 has broadcast 1 distinct callsign, including GASAL.