Apparatus

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sensors Mode-S transponder

400A18

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-NWEM · AIRBUS HELICOPTERS EC-135/635

Hex
400A18
Octal
20005030
Decimal
4,196,888
Country
GB
Tail
G-NWEM
Type
EC35
No current signal · last broadcast 11d ago
Flights observed
178
Distinct callsigns
2
Country
GB
Last broadcast
11d ago

Last known position

Most recent position reported by Mode-S 400A18.

Country allocation

The ICAO 24-bit address 400A18 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 2 distinct

Callsign Airline Flights Last seen
HLE75 - 90 2026-07-03
HLE72 - 88 2026-05-19

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-03 HLE75 - Jul 3, 15:35 UTCJul 3, 16:15 UTC40m
2026-07-03 HLE75 - Jul 3, 12:25 UTCJul 3, 12:40 UTC15m
2026-07-03 HLE75 - Jul 3, 10:20 UTCJul 3, 10:30 UTC10m
2026-07-03 HLE75 - Jul 3, 08:00 UTCJul 3, 08:10 UTC10m
2026-07-01 HLE75 - Jul 1, 11:55 UTCJul 1, 12:05 UTC10m
2026-07-01 HLE75 - Jul 1, 08:35 UTCJul 1, 08:45 UTC10m
2026-06-30 HLE75 - Jun 30, 14:40 UTCJun 30, 15:40 UTC1h 0m
2026-06-30 HLE75 - Jun 30, 13:15 UTCJun 30, 13:40 UTC25m
2026-06-30 HLE75 - Jun 30, 11:45 UTCJun 30, 12:20 UTC35m
2026-06-30 HLE75 - Jun 30, 10:00 UTCJun 30, 10:15 UTC15m
2026-06-28 HLE75 - Jun 28, 18:44 UTCJun 28, 18:55 UTC10m
2026-06-28 HLE75 - Jun 28, 16:45 UTCJun 28, 17:25 UTC40m
2026-06-27 HLE75 - Jun 27, 16:49 UTCJun 27, 16:59 UTC10m
2026-06-27 HLE75 - Jun 27, 15:49 UTCJun 27, 16:00 UTC10m
2026-06-27 HLE75 - Jun 27, 14:09 UTCJun 27, 14:29 UTC20m
2026-06-27 HLE75 - Jun 27, 09:19 UTCJun 27, 09:34 UTC15m
2026-06-26 HLE75 - Jun 26, 12:29 UTCJun 26, 12:59 UTC30m
2026-06-26 HLE75 - Jun 26, 08:10 UTCJun 26, 09:05 UTC55m
2026-06-25 HLE75 - Jun 25, 16:29 UTCJun 25, 16:39 UTC10m
2026-06-25 HLE75 - Jun 25, 15:34 UTCJun 25, 15:50 UTC15m
2026-06-25 HLE75 - Jun 25, 12:19 UTCJun 25, 12:30 UTC10m
2026-06-24 HLE75 - Jun 24, 14:50 UTCJun 24, 15:29 UTC40m
2026-06-24 HLE75 - Jun 24, 11:20 UTCJun 24, 11:54 UTC35m
2026-06-23 HLE75 - Jun 23, 12:45 UTCJun 23, 12:55 UTC10m
2026-06-23 HLE75 - Jun 23, 11:29 UTCJun 23, 11:40 UTC10m
2026-06-22 HLE75 - Jun 22, 13:49 UTCJun 22, 14:05 UTC15m
2026-06-22 HLE75 - Jun 22, 12:05 UTCJun 22, 12:15 UTC10m
2026-06-21 HLE75 - Jun 21, 17:20 UTCJun 21, 17:29 UTC10m
2026-06-21 HLE75 - Jun 21, 09:40 UTCJun 21, 09:49 UTC10m
2026-06-20 HLE75 - Jun 20, 17:24 UTCJun 20, 17:39 UTC15m
2026-06-20 HLE75 - Jun 20, 15:44 UTCJun 20, 16:29 UTC45m
2026-06-20 HLE75 - Jun 20, 14:29 UTCJun 20, 14:39 UTC10m
2026-06-20 HLE75 - Jun 20, 08:05 UTCJun 20, 08:14 UTC10m
2026-06-19 HLE75 - Jun 19, 11:14 UTCJun 19, 11:54 UTC40m
2026-06-18 HLE75 - Jun 18, 16:15 UTCJun 18, 16:30 UTC15m
2026-06-18 HLE75 - Jun 18, 15:05 UTCJun 18, 15:40 UTC35m
2026-06-17 HLE75 - Jun 17, 15:00 UTCJun 17, 15:10 UTC10m
2026-06-17 HLE75 - Jun 17, 13:55 UTCJun 17, 14:05 UTC10m
2026-06-17 HLE75 - Jun 17, 09:35 UTCJun 17, 09:45 UTC10m
2026-06-17 HLE75 - Jun 17, 07:25 UTCJun 17, 07:40 UTC15m
2026-06-15 HLE75 - Jun 15, 14:45 UTCJun 15, 15:00 UTC15m
2026-06-15 HLE75 - Jun 15, 09:00 UTCJun 15, 09:10 UTC10m
2026-06-14 HLE75 - Jun 14, 17:10 UTCJun 14, 17:40 UTC30m
2026-06-13 HLE75 - Jun 13, 08:25 UTCJun 13, 09:25 UTC1h 0m
2026-06-12 HLE75 - Jun 12, 15:45 UTCJun 12, 16:00 UTC15m
2026-06-11 HLE75 - Jun 11, 11:00 UTCJun 11, 11:25 UTC25m
2026-06-10 HLE75 - Jun 10, 07:50 UTCJun 10, 08:00 UTC10m
2026-06-09 HLE75 - Jun 9, 18:30 UTCJun 9, 18:40 UTC10m
2026-06-09 HLE75 - Jun 9, 13:05 UTCJun 9, 14:35 UTC1h 30m
2026-06-09 HLE75 - Jun 9, 10:50 UTCJun 9, 11:00 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-NWEM page for operator, model, and routing details .

Mode-S 400A18 frequently asked

What is Mode-S code 400A18?
400A18 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-NWEM.
Where is Mode-S 400A18 registered?
Mode-S code 400A18 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 400A18 broadcasting right now?
No active broadcast right now. Last signal was 11d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 400A18, octal 20005030, decimal 4,196,888.
What flights does 400A18 operate?
Mode-S 400A18 has broadcast 2 distinct callsigns, including HLE75, HLE72.