Apparatus

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sensors Mode-S transponder

40838B

ICAO 24-bit transponder address · allocated to United Kingdom

Hex
40838B
Octal
20101613
Decimal
4,227,979
Country
GB
Broadcasting now · callsign BAW874 · 36,975 ft
Flights observed
318
Distinct callsigns
20
Country
GB
Last broadcast
18d ago

Current position

40838B is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 40838B 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 20 distinct

Callsign Airline Flights Last seen
BAW707 British Airways 7 2026-07-20
BAW706 British Airways 7 2026-07-20
SHT15B - 5 2026-06-29
SHT14G - 5 2026-06-29
BAW890 British Airways 4 2026-07-26
BAW689 British Airways 4 2026-07-23
BAW639 - 4 2026-07-08
BAW638 - 4 2026-07-07
BAW522 - 4 2026-06-20
SHT13Z - 3 2026-07-12
SHT12U - 3 2026-07-11
BAW94DL British Airways 3 2026-06-19
BAW837 - 3 2026-07-14
BAW721 - 3 2026-07-18
BAW720 - 3 2026-07-17
BAW71LK - 3 2026-06-30
BAW710C - 3 2026-06-29
BAW68TR British Airways 3 2026-07-23
BAW63VP - 3 2026-07-09
BAW630 British Airways 3 2026-07-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 BAW890 LHR → SOF Jul 26, 20:50 UTCJul 26, 22:45 UTC1h 55m
2026-07-26 BAW505 FAO → LHR Jul 26, 16:25 UTCJul 26, 18:50 UTC2h 25m
2026-07-26 BAW5DW LHR → LIS Jul 26, 12:55 UTCJul 26, 15:00 UTC2h 5m
2026-07-26 BAW547 FCO → LHR Jul 26, 09:20 UTCJul 26, 11:25 UTC2h 5m
2026-07-26 BAW5PQ LHR → FCO Jul 26, 05:35 UTCJul 26, 07:25 UTC1h 51m
2026-07-25 BAW661 LCA → LHR Jul 25, 18:00 UTCJul 25, 21:05 UTC3h 5m
2026-07-25 BAW66GA ATH → LHR Jul 25, 13:00 UTCJul 25, 15:50 UTC2h 50m
2026-07-25 BAW761 OSL → LHR Jul 25, 10:20 UTCJul 25, 11:40 UTC1h 20m
2026-07-25 BAW760 LHR → OSL Jul 25, 07:50 UTCJul 25, 09:00 UTC1h 10m
2026-07-25 BAW765 INN → LHR Jul 25, 04:50 UTCJul 25, 06:05 UTC1h 15m
2026-07-24 BAW764 LHR → INN Jul 24, 19:40 UTCJul 24, 20:45 UTC1h 5m
2026-07-24 BAW505 FAO → LHR Jul 24, 15:45 UTCJul 24, 17:55 UTC2h 10m
2026-07-24 BAW5DW LHR → LIS Jul 24, 12:05 UTCJul 24, 14:25 UTC2h 20m
2026-07-24 SHT15D JER → LHR Jul 24, 09:35 UTCJul 24, 10:10 UTC35m
2026-07-24 SHT14L - Jul 24, 07:55 UTCJul 24, 08:30 UTC35m
2026-07-24 SHT7A GLA → LHR Jul 24, 05:00 UTCJul 24, 05:55 UTC55m
2026-07-23 SHT6A - Jul 23, 19:45 UTCJul 23, 20:40 UTC55m
2026-07-23 BAW689 IST → LHR Jul 23, 14:40 UTCJul 23, 18:25 UTC3h 45m
2026-07-23 BAW68TR LHR → JTR Jul 23, 10:05 UTCJul 23, 13:10 UTC3h 5m
2026-07-23 BAW6NL LIN → LHR Jul 23, 05:00 UTCJul 23, 07:15 UTC2h 15m
2026-07-22 BAW564Y LHR → LIN Jul 22, 19:50 UTCJul 22, 21:45 UTC1h 55m
2026-07-22 BAW38DB - Jul 22, 17:35 UTCJul 22, 18:30 UTC55m
2026-07-22 BAW84W - Jul 22, 15:30 UTCJul 22, 16:25 UTC55m
2026-07-22 BAW305 - Jul 22, 12:20 UTCJul 22, 13:25 UTC1h 5m
2026-07-22 BAW3VH - Jul 22, 11:20 UTCJul 22, 11:35 UTC15m
2026-07-21 BAW530 LHR → SPU Jul 21, 17:45 UTCJul 21, 19:40 UTC1h 55m
2026-07-21 BAW73V GVA → LHR Jul 21, 14:55 UTCJul 21, 16:20 UTC1h 25m
2026-07-21 BAW736 LHR → GVA Jul 21, 12:25 UTCJul 21, 13:35 UTC1h 10m
2026-07-21 BAW473D BCN → LHR Jul 21, 08:35 UTCJul 21, 10:25 UTC1h 50m
2026-07-21 BAW472M LHR → BCN Jul 21, 05:25 UTCJul 21, 07:00 UTC1h 35m
2026-07-20 BAW707 ZRH → LHR Jul 20, 15:40 UTCJul 20, 20:15 UTC4h 35m
2026-07-20 BAW706 LHR → VIE Jul 20, 10:05 UTCJul 20, 14:10 UTC4h 5m
2026-07-20 BAW779C ARN → LHR Jul 20, 06:05 UTCJul 20, 08:25 UTC2h 20m
2026-07-19 BAW778F - Jul 19, 19:55 UTCJul 19, 22:00 UTC2h 5m
2026-07-19 BAW995 BER → LHR Jul 19, 16:55 UTCJul 19, 18:25 UTC1h 30m
2026-07-19 BAW994 LHR → BER Jul 19, 14:10 UTCJul 19, 15:40 UTC1h 30m
2026-07-19 BAW469 - Jul 19, 10:15 UTCJul 19, 12:35 UTC2h 20m
2026-07-19 BAW468 - Jul 19, 06:45 UTCJul 19, 08:35 UTC1h 50m
2026-07-18 BAW65LG JMK → LHR Jul 18, 16:05 UTCJul 18, 19:35 UTC3h 30m
2026-07-18 BAW26AV LHR → ATH Jul 18, 11:15 UTCJul 18, 14:15 UTC3h 0m
2026-07-18 BAW721 - Jul 18, 05:35 UTCJul 18, 09:05 UTC3h 30m
2026-07-17 BAW720 - Jul 17, 18:29 UTCJul 17, 21:34 UTC3h 5m
2026-07-17 BAW425 - Jul 17, 14:15 UTCJul 17, 16:40 UTC2h 25m
2026-07-17 BAW424 - Jul 17, 10:35 UTCJul 17, 12:55 UTC2h 20m
2026-07-17 BAW891 TBS → LHR Jul 17, 03:25 UTCJul 17, 08:40 UTC5h 15m
2026-07-17 BAW890 - Jul 17, 00:55 UTCJul 17, 01:09 UTC15m
2026-07-16 BAW890 - Jul 16, 20:45 UTCJul 16, 23:55 UTC3h 10m
2026-07-16 SHT7P GLA → LHR Jul 16, 17:54 UTCJul 16, 19:05 UTC1h 10m
2026-07-16 SHT6F - Jul 16, 16:00 UTCJul 16, 16:55 UTC55m
2026-07-16 BAW811N DUB → LHR Jul 16, 13:30 UTCJul 16, 14:29 UTC1h 0m

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 40838B frequently asked

What is Mode-S code 40838B?
40838B is an ICAO 24-bit transponder address. Allocated to United Kingdom.
Where is Mode-S 40838B registered?
Mode-S code 40838B 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 40838B broadcasting right now?
Yes. Mode-S 40838B is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40838B, octal 20101613, decimal 4,227,979.
What flights does 40838B operate?
Mode-S 40838B has broadcast 20 distinct callsigns, including BAW707, BAW706, SHT15B, SHT14G, BAW890.