sensors Mode-S transponder

40125C

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-BNNO · PIPER PA-28-140/150/160/180

Hex
40125C
Octal
20011134
Decimal
4,199,004
Country
GB
Tail
G-BNNO
Type
P28A
No current signal · last broadcast 11h ago
Flights observed
47
Distinct callsigns
1
Country
GB
Last broadcast
11h ago

Last known position

Most recent position reported by Mode-S 40125C.

Country allocation

The ICAO 24-bit address 40125C 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
GBNNO - 47 2026-07-26

Recent flights last 47

DateFlightRouteTakeoffLandingDuration
2026-07-26 GBNNO - Jul 26, 10:05 UTCJul 26, 10:35 UTC30m
2026-07-25 GBNNO - Jul 25, 16:35 UTCJul 25, 17:30 UTC55m
2026-07-25 GBNNO - Jul 25, 06:10 UTCJul 25, 06:45 UTC35m
2026-07-24 GBNNO - Jul 24, 14:35 UTCJul 24, 15:50 UTC1h 15m
2026-07-24 GBNNO - Jul 24, 07:55 UTCJul 24, 09:30 UTC1h 35m
2026-07-23 GBNNO - Jul 23, 13:20 UTCJul 23, 13:50 UTC30m
2026-07-23 GBNNO - Jul 23, 12:05 UTCJul 23, 12:15 UTC10m
2026-07-20 GBNNO - Jul 20, 13:20 UTCJul 20, 14:05 UTC45m
2026-07-20 GBNNO - Jul 20, 10:15 UTCJul 20, 11:05 UTC50m
2026-07-12 GBNNO - Jul 12, 08:05 UTCJul 12, 09:50 UTC1h 45m
2026-07-10 GBNNO - Jul 10, 09:40 UTCJul 10, 11:10 UTC1h 30m
2026-07-09 GBNNO - Jul 9, 15:00 UTCJul 9, 16:25 UTC1h 25m
2026-07-09 GBNNO - Jul 9, 11:30 UTCJul 9, 13:05 UTC1h 35m
2026-07-04 GBNNO - Jul 4, 14:30 UTCJul 4, 15:10 UTC40m
2026-07-04 GBNNO - Jul 4, 11:45 UTCJul 4, 12:15 UTC30m
2026-07-04 GBNNO - Jul 4, 10:15 UTCJul 4, 10:50 UTC35m
2026-07-03 GBNNO - Jul 3, 10:10 UTCJul 3, 10:25 UTC15m
2026-06-30 GBNNO - Jun 30, 09:10 UTCJun 30, 09:45 UTC35m
2026-06-29 GBNNO - Jun 29, 15:09 UTCJun 29, 16:59 UTC1h 50m
2026-06-29 GBNNO - Jun 29, 13:54 UTCJun 29, 14:34 UTC40m
2026-06-27 GBNNO - Jun 27, 15:45 UTCJun 27, 16:39 UTC55m
2026-06-27 GBNNO - Jun 27, 12:19 UTCJun 27, 13:20 UTC1h 0m
2026-06-26 GBNNO - Jun 26, 08:45 UTCJun 26, 08:54 UTC10m
2026-06-13 GBNNO - Jun 13, 10:45 UTCJun 13, 12:05 UTC1h 20m
2026-06-12 GBNNO - Jun 12, 17:05 UTCJun 12, 19:10 UTC2h 5m
2026-06-12 GBNNO - Jun 12, 11:30 UTCJun 12, 14:25 UTC2h 55m
2026-06-12 GBNNO - Jun 12, 09:55 UTCJun 12, 10:20 UTC25m
2026-06-12 GBNNO - Jun 12, 07:45 UTCJun 12, 08:45 UTC1h 0m
2026-06-11 GBNNO - Jun 11, 14:15 UTCJun 11, 16:30 UTC2h 15m
2026-06-11 GBNNO - Jun 11, 08:30 UTCJun 11, 12:45 UTC4h 15m
2026-06-11 GBNNO - Jun 11, 07:05 UTCJun 11, 07:40 UTC35m
2026-06-10 GBNNO - Jun 10, 11:05 UTCJun 10, 11:15 UTC10m
2026-06-05 GBNNO - Jun 5, 10:35 UTCJun 5, 11:15 UTC40m
2026-05-29 GBNNO - May 29, 13:05 UTCMay 29, 13:45 UTC40m
2026-05-14 GBNNO - May 14, 11:30 UTCMay 14, 13:01 UTC1h 30m
2026-05-08 GBNNO - May 8, 14:50 UTCMay 8, 15:25 UTC35m
2026-05-08 GBNNO - May 8, 10:19 UTCMay 8, 11:40 UTC1h 20m
2026-05-07 GBNNO - May 7, 15:55 UTCMay 7, 16:10 UTC15m
2026-05-07 GBNNO - May 7, 13:25 UTCMay 7, 14:05 UTC40m
2026-05-07 GBNNO - May 7, 10:50 UTCMay 7, 11:25 UTC35m
2026-05-07 GBNNO - May 7, 08:55 UTCMay 7, 09:25 UTC30m
2026-04-27 GBNNO - Apr 27, 16:10 UTCApr 27, 17:15 UTC1h 5m
2026-04-27 GBNNO - Apr 27, 13:25 UTCApr 27, 13:55 UTC30m
2026-04-25 GBNNO - Apr 25, 15:15 UTCApr 25, 16:35 UTC1h 20m
2026-04-25 GBNNO - Apr 25, 13:25 UTCApr 25, 14:10 UTC45m
2026-04-18 GBNNO - Apr 18, 11:40 UTCApr 18, 12:30 UTC50m
2026-04-18 GBNNO - Apr 18, 09:45 UTCApr 18, 10:40 UTC55m

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

Mode-S 40125C frequently asked

What is Mode-S code 40125C?
40125C is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-BNNO.
Where is Mode-S 40125C registered?
Mode-S code 40125C 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 40125C broadcasting right now?
No active broadcast right now. Last signal was 11h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40125C, octal 20011134, decimal 4,199,004.
What flights does 40125C operate?
Mode-S 40125C has broadcast 1 distinct callsign, including GBNNO.