sensors Mode-S transponder

40809C

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-FTRO · CESSNA 152

Hex
40809C
Octal
20100234
Decimal
4,227,228
Country
GB
Tail
G-FTRO
Type
C152
No current signal · last broadcast 15h ago
Flights observed
5
Distinct callsigns
1
Country
GB
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S 40809C.

Country allocation

The ICAO 24-bit address 40809C 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
GFTRO - 5 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 GFTRO - Apr 14, 10:10 UTCApr 14, 10:50 UTC40m
2026-04-13 GFTRO - Apr 13, 13:40 UTCApr 13, 13:55 UTC15m
2026-04-13 GFTRO - Apr 13, 10:40 UTCApr 13, 11:20 UTC40m
2026-04-13 GFTRO - Apr 13, 09:20 UTCApr 13, 09:55 UTC35m
2026-04-13 GFTRO - Apr 13, 08:20 UTCApr 13, 08:35 UTC15m

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

Mode-S 40809C frequently asked

What is Mode-S code 40809C?
40809C is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-FTRO.
Where is Mode-S 40809C registered?
Mode-S code 40809C 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 40809C broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40809C, octal 20100234, decimal 4,227,228.
What flights does 40809C operate?
Mode-S 40809C has broadcast 1 distinct callsign, including GFTRO.