sensors Mode-S transponder

407D91

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-UNIB · AGUSTA AW-169

Hex
407D91
Octal
20076621
Decimal
4,226,449
Country
GB
Tail
G-UNIB
Type
A169
No current signal · last broadcast 16h ago
Flights observed
8
Distinct callsigns
1
Country
GB
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 407D91.

Country allocation

The ICAO 24-bit address 407D91 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
UFX62 - 8 2026-04-14

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 UFX62 - Apr 14, 09:10 UTCApr 14, 09:25 UTC15m
2026-04-14 UFX62 - Apr 14, 08:50 UTCApr 14, 09:05 UTC15m
2026-04-14 UFX62 - Apr 14, 07:10 UTCApr 14, 07:35 UTC25m
2026-04-13 UFX62 - Apr 13, 14:50 UTCApr 13, 15:25 UTC35m
2026-04-13 UFX62 - Apr 13, 12:20 UTCApr 13, 12:50 UTC30m
2026-04-13 UFX62 - Apr 13, 08:20 UTCApr 13, 08:50 UTC30m
2026-04-13 UFX62 - Apr 13, 07:55 UTCApr 13, 08:50 UTC55m
2026-04-13 UFX62 - Apr 13, 07:25 UTCApr 13, 08:15 UTC50m

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

Mode-S 407D91 frequently asked

What is Mode-S code 407D91?
407D91 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-UNIB.
Where is Mode-S 407D91 registered?
Mode-S code 407D91 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 407D91 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 407D91, octal 20076621, decimal 4,226,449.
What flights does 407D91 operate?
Mode-S 407D91 has broadcast 1 distinct callsign, including UFX62.