Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

401ADD

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-BBKB · CESSNA 150

Hex
401ADD
Octal
20015335
Decimal
4,201,181
Country
GB
Tail
G-BBKB
Type
C150
No current signal · last broadcast 12h ago
Flights observed
207
Distinct callsigns
1
Country
GB
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 401ADD.

Country allocation

The ICAO 24-bit address 401ADD 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
GBBKB - 207 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 GBBKB - Jul 17, 17:30 UTCJul 17, 18:25 UTC55m
2026-07-17 GBBKB - Jul 17, 10:40 UTCJul 17, 13:00 UTC2h 20m
2026-07-17 GBBKB - Jul 17, 08:30 UTCJul 17, 09:50 UTC1h 20m
2026-07-16 GBBKB - Jul 16, 17:20 UTCJul 16, 18:10 UTC50m
2026-07-16 GBBKB - Jul 16, 15:45 UTCJul 16, 16:44 UTC1h 0m
2026-07-16 GBBKB - Jul 16, 14:50 UTCJul 16, 15:14 UTC25m
2026-07-16 GBBKB - Jul 16, 10:35 UTCJul 16, 13:00 UTC2h 25m
2026-07-15 GBBKB - Jul 15, 14:20 UTCJul 15, 15:55 UTC1h 35m
2026-07-15 GBBKB - Jul 15, 10:55 UTCJul 15, 12:15 UTC1h 20m
2026-07-14 GBBKB - Jul 14, 14:35 UTCJul 14, 15:15 UTC40m
2026-07-14 GBBKB - Jul 14, 10:50 UTCJul 14, 13:15 UTC2h 25m
2026-07-14 GBBKB - Jul 14, 09:05 UTCJul 14, 09:55 UTC50m
2026-07-13 GBBKB - Jul 13, 15:15 UTCJul 13, 15:50 UTC35m
2026-07-13 GBBKB - Jul 13, 10:20 UTCJul 13, 12:20 UTC2h 0m
2026-07-12 GBBKB - Jul 12, 14:35 UTCJul 12, 15:45 UTC1h 10m
2026-07-12 GBBKB - Jul 12, 12:45 UTCJul 12, 13:30 UTC45m
2026-07-12 GBBKB - Jul 12, 08:55 UTCJul 12, 09:40 UTC45m
2026-07-11 GBBKB - Jul 11, 14:50 UTCJul 11, 15:35 UTC45m
2026-07-11 GBBKB - Jul 11, 10:55 UTCJul 11, 13:20 UTC2h 25m
2026-07-10 GBBKB - Jul 10, 12:45 UTCJul 10, 13:35 UTC50m
2026-07-10 GBBKB - Jul 10, 11:05 UTCJul 10, 11:55 UTC50m
2026-07-10 GBBKB - Jul 10, 09:15 UTCJul 10, 09:40 UTC25m
2026-07-06 GBBKB - Jul 6, 13:25 UTCJul 6, 13:55 UTC30m
2026-07-05 GBBKB - Jul 5, 11:20 UTCJul 5, 11:50 UTC30m
2026-07-05 GBBKB - Jul 5, 09:10 UTCJul 5, 10:15 UTC1h 5m
2026-07-04 GBBKB - Jul 4, 17:35 UTCJul 4, 18:15 UTC40m
2026-07-04 GBBKB - Jul 4, 16:15 UTCJul 4, 17:00 UTC45m
2026-07-04 GBBKB - Jul 4, 14:20 UTCJul 4, 15:00 UTC40m
2026-07-04 GBBKB - Jul 4, 12:35 UTCJul 4, 13:10 UTC35m
2026-07-04 GBBKB - Jul 4, 10:35 UTCJul 4, 11:25 UTC50m
2026-07-04 GBBKB - Jul 4, 08:35 UTCJul 4, 09:10 UTC35m
2026-07-03 GBBKB - Jul 3, 13:25 UTCJul 3, 13:45 UTC20m
2026-07-03 GBBKB - Jul 3, 11:20 UTCJul 3, 12:15 UTC55m
2026-07-03 GBBKB - Jul 3, 08:25 UTCJul 3, 09:10 UTC45m
2026-07-02 GBBKB - Jul 2, 16:40 UTCJul 2, 17:00 UTC20m
2026-06-30 GBBKB - Jun 30, 11:35 UTCJun 30, 12:50 UTC1h 15m
2026-06-30 GBBKB - Jun 30, 10:50 UTCJun 30, 11:15 UTC25m
2026-06-29 GBBKB - Jun 29, 10:29 UTCJun 29, 11:50 UTC1h 20m
2026-06-28 GBBKB - Jun 28, 14:09 UTCJun 28, 14:50 UTC40m
2026-06-28 GBBKB - Jun 28, 12:44 UTCJun 28, 13:29 UTC45m
2026-06-28 GBBKB - Jun 28, 10:30 UTCJun 28, 10:44 UTC15m
2026-06-28 GBBKB - Jun 28, 08:25 UTCJun 28, 10:10 UTC1h 45m
2026-06-27 GBBKB - Jun 27, 15:34 UTCJun 27, 17:09 UTC1h 35m
2026-06-27 GBBKB - Jun 27, 10:34 UTCJun 27, 11:25 UTC50m
2026-06-26 GBBKB - Jun 26, 16:54 UTCJun 26, 19:24 UTC2h 30m
2026-06-26 GBBKB - Jun 26, 11:40 UTCJun 26, 13:19 UTC1h 40m
2026-06-26 GBBKB - Jun 26, 10:10 UTCJun 26, 11:05 UTC55m
2026-06-26 GBBKB - Jun 26, 08:34 UTCJun 26, 09:20 UTC45m
2026-06-24 GBBKB - Jun 24, 14:55 UTCJun 24, 15:49 UTC55m
2026-06-24 GBBKB - Jun 24, 14:00 UTCJun 24, 14:15 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-BBKB page for operator, model, and routing details .

Mode-S 401ADD frequently asked

What is Mode-S code 401ADD?
401ADD is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-BBKB.
Where is Mode-S 401ADD registered?
Mode-S code 401ADD 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 401ADD broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 401ADD, octal 20015335, decimal 4,201,181.
What flights does 401ADD operate?
Mode-S 401ADD has broadcast 1 distinct callsign, including GBBKB.