sensors Mode-S transponder

408345

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-MILS · PILATUS PC-12

Hex
408345
Octal
20101505
Decimal
4,227,909
Country
GB
Tail
G-MILS
Type
PC12
Broadcasting now · callsign GMILS · 12,700 ft
Flights observed
12
Distinct callsigns
1
Country
GB
Last broadcast
1h ago

Current position

408345 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 408345 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
GMILS - 12 2026-04-18

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-04-18 GMILS - Apr 18, 15:25 UTCApr 18, 16:15 UTC50m
2026-04-18 GMILS - Apr 18, 14:25 UTCApr 18, 15:10 UTC45m
2026-04-18 GMILS - Apr 18, 12:40 UTCApr 18, 12:55 UTC15m
2026-04-18 GMILS - Apr 18, 12:15 UTCApr 18, 12:25 UTC10m
2026-04-18 GMILS - Apr 18, 11:20 UTCApr 18, 12:00 UTC40m
2026-04-17 GMILS - Apr 17, 13:20 UTCApr 17, 15:10 UTC1h 50m
2026-04-17 GMILS - Apr 17, 13:05 UTCApr 17, 13:15 UTC10m
2026-04-17 GMILS - Apr 17, 10:15 UTCApr 17, 10:45 UTC30m
2026-04-17 GMILS - Apr 17, 09:20 UTCApr 17, 09:45 UTC25m
2026-04-17 GMILS - Apr 17, 08:20 UTCApr 17, 09:15 UTC55m
2026-04-15 GMILS - Apr 15, 13:30 UTCApr 15, 14:40 UTC1h 10m
2026-04-15 GMILS - Apr 15, 12:15 UTCApr 15, 12:40 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-MILS page for operator, model, and routing details .

Mode-S 408345 frequently asked

What is Mode-S code 408345?
408345 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-MILS.
Where is Mode-S 408345 registered?
Mode-S code 408345 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 408345 broadcasting right now?
Yes. Mode-S 408345 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 408345, octal 20101505, decimal 4,227,909.
What flights does 408345 operate?
Mode-S 408345 has broadcast 1 distinct callsign, including GMILS.