sensors Mode-S transponder

400EB4

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-BYYA · GROB G-115

Hex
400EB4
Octal
20007264
Decimal
4,198,068
Country
GB
Tail
G-BYYA
Type
G115
No current signal · last broadcast 15h ago
Flights observed
41
Distinct callsigns
16
Country
GB
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S 400EB4.

Country allocation

The ICAO 24-bit address 400EB4 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 16 distinct

Callsign Airline Flights Last seen
UAX68 - 11 2026-05-29
UAX62 - 6 2026-05-15
UAQ13 - 4 2026-05-27
UAQ11 - 3 2026-04-27
UAQ04 - 3 2026-05-28
UAX61 - 2 2026-05-15
UAQ21 - 2 2026-05-22
UAQ07 - 2 2026-04-16
UAX88 - 1 2026-04-23
UAX72 - 1 2026-04-24
UAX65 - 1 2026-04-13
UAX63 - 1 2026-04-20
UAQ23 - 1 2026-04-22
UAQ03 - 1 2026-05-14
GEORDIE2 - 1 2026-04-17
GEORDIE1 - 1 2026-04-22

Recent flights last 41

DateFlightRouteTakeoffLandingDuration
2026-05-29 UAX68 - May 29, 11:00 UTCMay 29, 11:25 UTC25m
2026-05-29 UAX68 - May 29, 09:00 UTCMay 29, 10:45 UTC1h 45m
2026-05-28 UAQ04 - May 28, 12:25 UTCMay 28, 13:40 UTC1h 15m
2026-05-28 UAQ04 - May 28, 09:45 UTCMay 28, 10:45 UTC1h 0m
2026-05-27 UAQ13 - May 27, 11:30 UTCMay 27, 12:45 UTC1h 15m
2026-05-27 UAQ13 - May 27, 08:35 UTCMay 27, 09:35 UTC1h 0m
2026-05-26 UAX68 - May 26, 09:09 UTCMay 26, 10:44 UTC1h 35m
2026-05-22 UAQ21 - May 22, 13:00 UTCMay 22, 13:55 UTC55m
2026-05-22 UAQ21 - May 22, 09:35 UTCMay 22, 11:55 UTC2h 20m
2026-05-21 UAQ13 - May 21, 13:05 UTCMay 21, 14:15 UTC1h 10m
2026-05-21 UAQ13 - May 21, 10:30 UTCMay 21, 11:45 UTC1h 15m
2026-05-20 UAX68 - May 20, 08:20 UTCMay 20, 09:10 UTC50m
2026-05-18 UAX68 - May 18, 09:35 UTCMay 18, 10:40 UTC1h 5m
2026-05-15 UAX62 - May 15, 12:45 UTCMay 15, 13:40 UTC55m
2026-05-15 UAX62 - May 15, 10:30 UTCMay 15, 11:40 UTC1h 10m
2026-05-15 UAX61 - May 15, 08:35 UTCMay 15, 09:40 UTC1h 5m
2026-05-14 UAQ03 - May 14, 13:15 UTCMay 14, 14:25 UTC1h 10m
2026-05-14 UAQ04 - May 14, 09:10 UTCMay 14, 10:15 UTC1h 5m
2026-05-13 UAX61 - May 13, 11:00 UTCMay 13, 11:50 UTC50m
2026-05-13 UAX62 - May 13, 08:30 UTCMay 13, 09:55 UTC1h 25m
2026-04-29 UAX62 - Apr 29, 12:55 UTCApr 29, 14:00 UTC1h 5m
2026-04-28 UAX62 - Apr 28, 14:25 UTCApr 28, 15:25 UTC1h 0m
2026-04-28 UAX62 - Apr 28, 12:40 UTCApr 28, 13:40 UTC1h 0m
2026-04-27 UAQ11 - Apr 27, 13:15 UTCApr 27, 14:15 UTC1h 0m
2026-04-24 UAX72 - Apr 24, 10:25 UTCApr 24, 12:15 UTC1h 50m
2026-04-23 UAX68 - Apr 23, 13:40 UTCApr 23, 15:25 UTC1h 45m
2026-04-23 UAX88 - Apr 23, 09:50 UTCApr 23, 12:55 UTC3h 5m
2026-04-22 GEORDIE1 - Apr 22, 14:05 UTCApr 22, 14:30 UTC25m
2026-04-22 UAQ23 - Apr 22, 08:10 UTCApr 22, 09:00 UTC50m
2026-04-21 UAX68 - Apr 21, 12:40 UTCApr 21, 14:20 UTC1h 40m
2026-04-21 UAX68 - Apr 21, 09:25 UTCApr 21, 11:10 UTC1h 45m
2026-04-20 UAX68 - Apr 20, 11:45 UTCApr 20, 14:10 UTC2h 25m
2026-04-20 UAX63 - Apr 20, 08:45 UTCApr 20, 09:15 UTC30m
2026-04-17 GEORDIE2 - Apr 17, 09:55 UTCApr 17, 10:25 UTC30m
2026-04-16 UAQ07 - Apr 16, 13:25 UTCApr 16, 13:54 UTC30m
2026-04-16 UAQ07 - Apr 16, 11:49 UTCApr 16, 13:05 UTC1h 15m
2026-04-16 UAX68 - Apr 16, 09:24 UTCApr 16, 10:49 UTC1h 25m
2026-04-15 UAX68 - Apr 15, 11:00 UTCApr 15, 11:40 UTC40m
2026-04-13 UAQ11 - Apr 13, 13:35 UTCApr 13, 14:50 UTC1h 15m
2026-04-13 UAQ11 - Apr 13, 10:30 UTCApr 13, 11:30 UTC1h 0m
2026-04-13 UAX65 - Apr 13, 09:10 UTCApr 13, 09:55 UTC45m

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-BYYA page for operator, model, and routing details .

Mode-S 400EB4 frequently asked

What is Mode-S code 400EB4?
400EB4 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-BYYA.
Where is Mode-S 400EB4 registered?
Mode-S code 400EB4 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 400EB4 broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 400EB4, octal 20007264, decimal 4,198,068.
What flights does 400EB4 operate?
Mode-S 400EB4 has broadcast 16 distinct callsigns, including UAX68, UAX62, UAQ13, UAQ11, UAQ04.