sensors Mode-S transponder

400D11

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-NICI · ROBINSON R-44 Raven

Hex
400D11
Octal
20006421
Decimal
4,197,649
Country
GB
Tail
G-NICI
Type
R44
No current signal · last broadcast 8d ago
Flights observed
33
Distinct callsigns
4
Country
GB
Last broadcast
8d ago

Last known position

Most recent position reported by Mode-S 400D11.

Country allocation

The ICAO 24-bit address 400D11 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 4 distinct

Callsign Airline Flights Last seen
COV15 - 25 2026-06-24
PIPE82 - 6 2026-06-26
COV20 - 1 2026-05-11
COV19 - 1 2026-06-24

Recent flights last 33

DateFlightRouteTakeoffLandingDuration
2026-06-26 PIPE82 - Jun 26, 12:14 UTCJun 26, 14:09 UTC1h 55m
2026-06-26 PIPE82 - Jun 26, 08:20 UTCJun 26, 10:50 UTC2h 30m
2026-06-25 PIPE82 - Jun 25, 15:10 UTCJun 25, 17:05 UTC1h 55m
2026-06-25 PIPE82 - Jun 25, 12:30 UTCJun 25, 14:24 UTC1h 55m
2026-06-25 PIPE82 - Jun 25, 08:40 UTCJun 25, 11:04 UTC2h 25m
2026-06-24 PIPE82 - Jun 24, 14:45 UTCJun 24, 16:54 UTC2h 10m
2026-06-24 COV19 - Jun 24, 12:40 UTCJun 24, 13:30 UTC50m
2026-06-24 COV15 - Jun 24, 10:35 UTCJun 24, 11:50 UTC1h 15m
2026-06-15 COV15 - Jun 15, 12:55 UTCJun 15, 13:10 UTC15m
2026-06-04 COV15 - Jun 4, 12:35 UTCJun 4, 13:30 UTC55m
2026-06-03 COV15 - Jun 3, 15:30 UTCJun 3, 15:45 UTC15m
2026-05-29 COV15 - May 29, 15:35 UTCMay 29, 15:45 UTC10m
2026-05-29 COV15 - May 29, 08:45 UTCMay 29, 08:55 UTC10m
2026-05-28 COV15 - May 28, 19:40 UTCMay 28, 20:40 UTC1h 0m
2026-05-28 COV15 - May 28, 13:30 UTCMay 28, 15:10 UTC1h 40m
2026-05-28 COV15 - May 28, 12:15 UTCMay 28, 12:25 UTC10m
2026-05-28 COV15 - May 28, 10:25 UTCMay 28, 11:40 UTC1h 15m
2026-05-27 COV15 - May 27, 19:25 UTCMay 27, 20:40 UTC1h 15m
2026-05-27 COV15 - May 27, 15:05 UTCMay 27, 16:50 UTC1h 45m
2026-05-27 COV15 - May 27, 10:20 UTCMay 27, 12:30 UTC2h 10m
2026-05-26 COV15 - May 26, 19:05 UTCMay 26, 20:40 UTC1h 35m
2026-05-26 COV15 - May 26, 13:15 UTCMay 26, 15:14 UTC2h 0m
2026-05-22 COV15 - May 22, 10:25 UTCMay 22, 12:35 UTC2h 10m
2026-05-22 COV15 - May 22, 09:45 UTCMay 22, 09:55 UTC10m
2026-05-21 COV15 - May 21, 18:55 UTCMay 21, 20:30 UTC1h 35m
2026-05-21 COV15 - May 21, 13:40 UTCMay 21, 15:30 UTC1h 50m
2026-05-21 COV15 - May 21, 10:55 UTCMay 21, 12:55 UTC2h 0m
2026-05-20 COV15 - May 20, 18:45 UTCMay 20, 20:30 UTC1h 45m
2026-05-20 COV15 - May 20, 15:25 UTCMay 20, 15:35 UTC10m
2026-05-20 COV15 - May 20, 13:20 UTCMay 20, 14:50 UTC1h 30m
2026-05-20 COV15 - May 20, 11:35 UTCMay 20, 11:45 UTC10m
2026-05-18 COV15 - May 18, 09:35 UTCMay 18, 09:55 UTC20m
2026-05-11 COV20 - May 11, 13:40 UTCMay 11, 15:15 UTC1h 35m

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

Mode-S 400D11 frequently asked

What is Mode-S code 400D11?
400D11 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-NICI.
Where is Mode-S 400D11 registered?
Mode-S code 400D11 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 400D11 broadcasting right now?
No active broadcast right now. Last signal was 8d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 400D11, octal 20006421, decimal 4,197,649.
What flights does 400D11 operate?
Mode-S 400D11 has broadcast 4 distinct callsigns, including COV15, PIPE82, COV20, COV19.