sensors Mode-S transponder

406A99

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-OXFB · PIPER PA-34 Seneca

Hex
406A99
Octal
20065231
Decimal
4,221,593
Country
GB
Tail
G-OXFB
Type
PA34
No current signal · last broadcast 22h ago
Flights observed
45
Distinct callsigns
6
Country
GB
Last broadcast
22h ago

Last known position

Most recent position reported by Mode-S 406A99.

Country allocation

The ICAO 24-bit address 406A99 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 6 distinct

Callsign Airline Flights Last seen
OXF26 - 15 2026-05-27
OXF14 - 13 2026-05-28
OXF33 - 9 2026-05-15
OXF45 - 4 2026-05-06
OXF42 - 3 2026-05-29
GOXFB - 1 2026-05-26

Recent flights last 45

DateFlightRouteTakeoffLandingDuration
2026-05-29 OXF42 - May 29, 12:45 UTCMay 29, 14:10 UTC1h 25m
2026-05-28 OXF14 OXF → OXF May 28, 08:30 UTCMay 28, 09:45 UTC1h 15m
2026-05-27 OXF26 - May 27, 10:10 UTCMay 27, 11:30 UTC1h 20m
2026-05-27 OXF26 OXF → OXF May 27, 07:45 UTCMay 27, 09:20 UTC1h 35m
2026-05-26 GOXFB - May 26, 10:34 UTCMay 26, 12:10 UTC1h 35m
2026-05-22 OXF14 - May 22, 11:40 UTCMay 22, 12:50 UTC1h 10m
2026-05-22 OXF14 - May 22, 08:35 UTCMay 22, 10:00 UTC1h 25m
2026-05-21 OXF42 - May 21, 13:05 UTCMay 21, 14:15 UTC1h 10m
2026-05-21 OXF26 - May 21, 10:45 UTCMay 21, 12:05 UTC1h 20m
2026-05-21 OXF26 - May 21, 08:20 UTCMay 21, 09:30 UTC1h 10m
2026-05-20 OXF26 - May 20, 09:00 UTCMay 20, 10:05 UTC1h 5m
2026-05-19 OXF26 - May 19, 12:55 UTCMay 19, 14:20 UTC1h 25m
2026-05-19 OXF26 OXF → OXF May 19, 09:25 UTCMay 19, 10:55 UTC1h 30m
2026-05-18 OXF14 - May 18, 11:20 UTCMay 18, 13:10 UTC1h 50m
2026-05-18 OXF14 - May 18, 08:10 UTCMay 18, 09:55 UTC1h 45m
2026-05-15 OXF33 - May 15, 15:10 UTCMay 15, 16:15 UTC1h 5m
2026-05-15 OXF33 - May 15, 13:25 UTCMay 15, 14:15 UTC50m
2026-05-15 OXF33 - May 15, 10:10 UTCMay 15, 11:10 UTC1h 0m
2026-05-15 OXF33 - May 15, 08:00 UTCMay 15, 08:55 UTC55m
2026-05-12 OXF26 OXF → OXF May 12, 12:10 UTCMay 12, 13:30 UTC1h 20m
2026-05-12 OXF26 - May 12, 08:40 UTCMay 12, 10:20 UTC1h 40m
2026-05-11 OXF14 OXF → OXF May 11, 15:05 UTCMay 11, 16:00 UTC55m
2026-05-11 OXF42 OXF → OXF May 11, 09:10 UTCMay 11, 10:45 UTC1h 35m
2026-05-06 OXF45 - May 6, 11:35 UTCMay 6, 13:10 UTC1h 35m
2026-05-06 OXF45 - May 6, 08:50 UTCMay 6, 10:30 UTC1h 40m
2026-05-05 OXF26 - May 5, 12:25 UTCMay 5, 13:50 UTC1h 25m
2026-05-05 OXF26 - May 5, 09:10 UTCMay 5, 10:40 UTC1h 30m
2026-04-21 OXF45 - Apr 21, 08:05 UTCApr 21, 09:40 UTC1h 35m
2026-04-20 OXF45 - Apr 20, 09:40 UTCApr 20, 11:45 UTC2h 5m
2026-04-17 OXF14 - Apr 17, 15:20 UTCApr 17, 15:30 UTC10m
2026-04-17 OXF14 - Apr 17, 14:10 UTCApr 17, 15:15 UTC1h 4m
2026-04-17 OXF33 - Apr 17, 11:20 UTCApr 17, 11:50 UTC30m
2026-04-17 OXF33 - Apr 17, 10:50 UTCApr 17, 11:15 UTC25m
2026-04-17 OXF33 - Apr 17, 09:20 UTCApr 17, 09:40 UTC20m
2026-04-17 OXF33 - Apr 17, 09:00 UTCApr 17, 09:15 UTC15m
2026-04-16 OXF33 - Apr 16, 13:40 UTCApr 16, 15:00 UTC1h 20m
2026-04-16 OXF26 - Apr 16, 09:10 UTCApr 16, 09:29 UTC20m
2026-04-16 OXF26 - Apr 16, 08:15 UTCApr 16, 09:05 UTC50m
2026-04-15 OXF26 - Apr 15, 11:00 UTCApr 15, 12:05 UTC1h 5m
2026-04-15 OXF26 - Apr 15, 10:45 UTCApr 15, 10:55 UTC10m
2026-04-15 OXF14 - Apr 15, 09:00 UTCApr 15, 09:25 UTC25m
2026-04-15 OXF14 - Apr 15, 08:10 UTCApr 15, 08:55 UTC45m
2026-04-14 OXF14 - Apr 14, 11:35 UTCApr 14, 12:45 UTC1h 10m
2026-04-14 OXF14 - Apr 14, 09:10 UTCApr 14, 09:35 UTC25m
2026-04-14 OXF14 - Apr 14, 08:20 UTCApr 14, 09:05 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-OXFB page for operator, model, and routing details .

Mode-S 406A99 frequently asked

What is Mode-S code 406A99?
406A99 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-OXFB.
Where is Mode-S 406A99 registered?
Mode-S code 406A99 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 406A99 broadcasting right now?
No active broadcast right now. Last signal was 22h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 406A99, octal 20065231, decimal 4,221,593.
What flights does 406A99 operate?
Mode-S 406A99 has broadcast 6 distinct callsigns, including OXF26, OXF14, OXF33, OXF45, OXF42.