sensors Mode-S transponder

424C9D

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to M-ASBA · BOMBARDIER BD-100 Challenger 350

Hex
424C9D
Octal
20446235
Decimal
4,344,989
Country
GB
Tail
M-ASBA
Type
CL35
No current signal · last broadcast 13h ago
Flights observed
7
Distinct callsigns
1
Country
GB
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 424C9D.

Country allocation

The ICAO 24-bit address 424C9D 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
MASBA - 7 2026-04-14

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 MASBA - Apr 14, 09:10 UTCApr 14, 09:40 UTC30m
2026-04-14 MASBA - Apr 14, 07:25 UTCApr 14, 09:05 UTC1h 40m
2026-04-13 MASBA - Apr 13, 12:20 UTCApr 13, 15:15 UTC2h 55m
2026-04-13 MASBA - Apr 13, 11:55 UTCApr 13, 12:15 UTC20m
2026-04-13 MASBA - Apr 13, 09:40 UTCApr 13, 10:30 UTC50m
2026-04-12 MASBA - Apr 12, 18:45 UTCApr 12, 19:50 UTC1h 5m
2026-04-12 MASBA - Apr 12, 17:15 UTCApr 12, 17:50 UTC35m

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 M-ASBA page for operator, model, and routing details .

Mode-S 424C9D frequently asked

What is Mode-S code 424C9D?
424C9D is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to M-ASBA.
Where is Mode-S 424C9D registered?
Mode-S code 424C9D 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 424C9D broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 424C9D, octal 20446235, decimal 4,344,989.
What flights does 424C9D operate?
Mode-S 424C9D has broadcast 1 distinct callsign, including MASBA.