sensors Mode-S transponder

40281D

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-ONHH · AIR PRODUCTS F-1 Aircoupe

Hex
40281D
Octal
20024035
Decimal
4,204,573
Country
GB
Tail
G-ONHH
Type
ERCO
No current signal · last broadcast 6h ago
Flights observed
19
Distinct callsigns
1
Country
GB
Last broadcast
6h ago

Last known position

Most recent position reported by Mode-S 40281D.

Country allocation

The ICAO 24-bit address 40281D 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
GONHH - 19 2026-07-05

Recent flights last 19

DateFlightRouteTakeoffLandingDuration
2026-07-05 GONHH - Jul 5, 15:50 UTCJul 5, 16:35 UTC45m
2026-07-05 GONHH - Jul 5, 10:00 UTCJul 5, 11:40 UTC1h 40m
2026-07-01 GONHH - Jul 1, 14:35 UTCJul 1, 15:50 UTC1h 15m
2026-06-30 GONHH - Jun 30, 16:45 UTCJun 30, 17:15 UTC30m
2026-06-30 GONHH - Jun 30, 10:55 UTCJun 30, 12:00 UTC1h 5m
2026-06-21 GONHH - Jun 21, 14:44 UTCJun 21, 15:54 UTC1h 10m
2026-06-21 GONHH - Jun 21, 10:29 UTCJun 21, 11:40 UTC1h 10m
2026-06-20 GONHH - Jun 20, 15:24 UTCJun 20, 16:24 UTC1h 0m
2026-06-14 GONHH - Jun 14, 14:10 UTCJun 14, 15:45 UTC1h 35m
2026-05-30 GONHH - May 30, 13:45 UTCMay 30, 14:50 UTC1h 5m
2026-05-29 GONHH - May 29, 15:55 UTCMay 29, 17:05 UTC1h 10m
2026-05-27 GONHH - May 27, 16:30 UTCMay 27, 17:30 UTC1h 0m
2026-05-27 GONHH - May 27, 12:50 UTCMay 27, 14:00 UTC1h 10m
2026-05-25 GONHH - May 25, 08:40 UTCMay 25, 09:45 UTC1h 5m
2026-05-23 GONHH - May 23, 13:55 UTCMay 23, 14:55 UTC1h 0m
2026-05-23 GONHH - May 23, 10:05 UTCMay 23, 11:20 UTC1h 15m
2026-05-16 GONHH - May 16, 09:06 UTCMay 16, 10:20 UTC1h 15m
2026-05-11 GONHH - May 11, 17:05 UTCMay 11, 17:40 UTC35m
2026-05-11 GONHH - May 11, 14:30 UTCMay 11, 14:55 UTC25m

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

Mode-S 40281D frequently asked

What is Mode-S code 40281D?
40281D is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-ONHH.
Where is Mode-S 40281D registered?
Mode-S code 40281D 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 40281D broadcasting right now?
No active broadcast right now. Last signal was 6h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40281D, octal 20024035, decimal 4,204,573.
What flights does 40281D operate?
Mode-S 40281D has broadcast 1 distinct callsign, including GONHH.