sensors Mode-S transponder

400ECE

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-BYUJ · GROB G-115

Hex
400ECE
Octal
20007316
Decimal
4,198,094
Country
GB
Tail
G-BYUJ
Type
G115
No current signal · last broadcast 3d ago
Flights observed
87
Distinct callsigns
20
Country
GB
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S 400ECE.

Country allocation

The ICAO 24-bit address 400ECE 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
UAO02 - 13 2026-06-19
UAO12 - 9 2026-06-19
UAO01 - 6 2026-06-02
NCKL40 - 6 2026-07-02
NCKL64 - 5 2026-07-09
NCKL15 - 5 2026-06-18
NCKL06 - 5 2026-06-11
NCKL22 - 4 2026-07-03
NCKL08 - 4 2026-06-16
UAO35 - 3 2026-06-30
UAO06 - 3 2026-06-17
NCKL18 - 3 2026-07-10
NCKL26 - 2 2026-05-29
CHRWL2 - 2 2026-06-22
UAY17 - 1 2026-04-24
UAO464 - 1 2026-05-28
UAO24 - 1 2026-04-14
NCKL60 - 1 2026-05-27
NCKL53 - 1 2026-04-22
NCKL46 - 1 2026-04-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-10 NCKL18 - Jul 10, 09:00 UTCJul 10, 10:15 UTC1h 15m
2026-07-09 NCKL64 BEX → BEX Jul 9, 09:15 UTCJul 9, 10:15 UTC1h 0m
2026-07-03 NCKL22 - Jul 3, 09:50 UTCJul 3, 10:15 UTC25m
2026-07-03 NCKL22 - Jul 3, 09:10 UTCJul 3, 09:30 UTC20m
2026-07-02 NCKL40 - Jul 2, 13:55 UTCJul 2, 15:30 UTC1h 35m
2026-07-02 NCKL40 - Jul 2, 10:05 UTCJul 2, 11:05 UTC1h 0m
2026-06-30 UAO35 BEX → BEX Jun 30, 15:05 UTCJun 30, 16:00 UTC55m
2026-06-30 UAO35 BEX → BEX Jun 30, 11:10 UTCJun 30, 12:40 UTC1h 30m
2026-06-22 CHRWL2 - Jun 22, 14:55 UTCJun 22, 15:54 UTC1h 0m
2026-06-22 CHRWL2 - Jun 22, 11:50 UTCJun 22, 12:30 UTC40m
2026-06-19 UAO12 BEX → BEX Jun 19, 14:04 UTCJun 19, 15:09 UTC1h 5m
2026-06-19 UAO02 BEX → BEX Jun 19, 09:19 UTCJun 19, 09:59 UTC40m
2026-06-18 NCKL25 - Jun 18, 14:25 UTCJun 18, 16:00 UTC1h 35m
2026-06-18 NCKL15 - Jun 18, 11:10 UTCJun 18, 13:40 UTC2h 30m
2026-06-17 NCKL07 - Jun 17, 13:15 UTCJun 17, 15:35 UTC2h 20m
2026-06-17 UAO06 BEX → BEX Jun 17, 10:00 UTCJun 17, 10:45 UTC45m
2026-06-16 NCKL15 BEX → BEX Jun 16, 15:35 UTCJun 16, 15:55 UTC20m
2026-06-16 NCKL08 BEX → BEX Jun 16, 13:44 UTCJun 16, 14:55 UTC1h 10m
2026-06-16 UAO02 - Jun 16, 11:15 UTCJun 16, 12:20 UTC1h 5m
2026-06-16 NCKL16 - Jun 16, 08:39 UTCJun 16, 09:34 UTC55m
2026-06-15 NCKL64 - Jun 15, 15:04 UTCJun 15, 15:50 UTC45m
2026-06-15 UAO12 - Jun 15, 10:09 UTCJun 15, 11:39 UTC1h 30m
2026-06-12 NCKL64 - Jun 12, 09:40 UTCJun 12, 10:25 UTC45m
2026-06-11 NCKL06 - Jun 11, 10:05 UTCJun 11, 11:05 UTC1h 0m
2026-06-04 UAO12 BEX → BEX Jun 4, 15:10 UTCJun 4, 15:55 UTC45m
2026-06-04 UAO02 - Jun 4, 12:35 UTCJun 4, 13:50 UTC1h 15m
2026-06-04 UAO12 - Jun 4, 09:30 UTCJun 4, 10:20 UTC50m
2026-06-03 UAO12 BEX → BEX Jun 3, 13:15 UTCJun 3, 14:00 UTC45m
2026-06-03 UAO12 BEX → BEX Jun 3, 09:05 UTCJun 3, 09:30 UTC25m
2026-06-02 UAO01 - Jun 2, 13:25 UTCJun 2, 14:05 UTC40m
2026-06-02 UAO02 - Jun 2, 10:50 UTCJun 2, 11:50 UTC1h 0m
2026-06-02 UAO06 BEX → BEX Jun 2, 09:25 UTCJun 2, 10:10 UTC45m
2026-06-01 UAO02 BEX → BEX Jun 1, 12:50 UTCJun 1, 13:55 UTC1h 5m
2026-06-01 CHRWL1 BEX → BEX Jun 1, 09:50 UTCJun 1, 10:40 UTC50m
2026-05-29 NCKL26 - May 29, 15:30 UTCMay 29, 15:45 UTC15m
2026-05-29 NCKL26 BEX → BZZ May 29, 08:45 UTCMay 29, 09:05 UTC20m
2026-05-28 UAO464 - May 28, 13:55 UTCMay 28, 15:05 UTC1h 10m
2026-05-28 NCKL31 - May 28, 10:45 UTCMay 28, 11:30 UTC45m
2026-05-28 UAO06 - May 28, 08:45 UTCMay 28, 09:25 UTC40m
2026-05-27 NCKL60 - May 27, 11:15 UTCMay 27, 12:10 UTC55m
2026-05-27 UAO02 - May 27, 09:05 UTCMay 27, 10:10 UTC1h 5m
2026-05-26 NCKL18 - May 26, 11:30 UTCMay 26, 11:54 UTC25m
2026-05-26 UAO02 - May 26, 09:19 UTCMay 26, 10:44 UTC1h 25m
2026-05-20 UAO12 BEX → BEX May 20, 12:35 UTCMay 20, 13:10 UTC35m
2026-05-18 UAO35 BEX → BEX May 18, 09:25 UTCMay 18, 10:50 UTC1h 25m
2026-05-15 NCKL20 - May 15, 12:25 UTCMay 15, 14:40 UTC2h 15m
2026-05-15 NCKL44 - May 15, 09:00 UTCMay 15, 11:30 UTC2h 30m
2026-05-14 UAO12 - May 14, 13:25 UTCMay 14, 14:25 UTC1h 0m
2026-05-14 NCKL45 - May 14, 09:45 UTCMay 14, 11:20 UTC1h 35m
2026-05-13 NCKL06 - May 13, 09:25 UTCMay 13, 10:25 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.

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

Mode-S 400ECE frequently asked

What is Mode-S code 400ECE?
400ECE is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-BYUJ.
Where is Mode-S 400ECE registered?
Mode-S code 400ECE 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 400ECE broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 400ECE, octal 20007316, decimal 4,198,094.
What flights does 400ECE operate?
Mode-S 400ECE has broadcast 20 distinct callsigns, including UAO02, UAO12, UAO01, NCKL40, NCKL64.