sensors Mode-S transponder

40816F

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-HMAA · AIRBUS HELICOPTERS EC-145

Hex
40816F
Octal
20100557
Decimal
4,227,439
Country
GB
Tail
G-HMAA
Type
EC45
No current signal · last broadcast 1d ago
Flights observed
11
Distinct callsigns
1
Country
GB
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 40816F.

Country allocation

The ICAO 24-bit address 40816F 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
HLE09 - 11 2026-04-17

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-17 HLE09 - Apr 17, 18:25 UTCApr 17, 18:55 UTC30m
2026-04-17 HLE09 - Apr 17, 15:55 UTCApr 17, 16:05 UTC10m
2026-04-17 HLE09 - Apr 17, 14:30 UTCApr 17, 14:45 UTC15m
2026-04-17 HLE09 - Apr 17, 12:25 UTCApr 17, 13:05 UTC40m
2026-04-15 HLE09 - Apr 15, 17:50 UTCApr 15, 18:00 UTC10m
2026-04-14 HLE09 - Apr 14, 19:05 UTCApr 14, 19:20 UTC15m
2026-04-14 HLE09 - Apr 14, 17:40 UTCApr 14, 17:50 UTC10m
2026-04-13 HLE09 - Apr 13, 19:05 UTCApr 13, 19:15 UTC10m
2026-04-13 HLE09 - Apr 13, 17:55 UTCApr 13, 18:05 UTC10m
2026-04-13 HLE09 - Apr 13, 16:20 UTCApr 13, 16:35 UTC15m
2026-04-13 HLE09 - Apr 13, 15:20 UTCApr 13, 15:30 UTC10m

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

Mode-S 40816F frequently asked

What is Mode-S code 40816F?
40816F is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-HMAA.
Where is Mode-S 40816F registered?
Mode-S code 40816F 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 40816F broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40816F, octal 20100557, decimal 4,227,439.
What flights does 40816F operate?
Mode-S 40816F has broadcast 1 distinct callsign, including HLE09.