sensors Mode-S transponder

43C921

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to ZM340 · BEECHCRAFT T-6 Texan 2

Hex
43C921
Octal
20744441
Decimal
4,442,401
Country
GB
Tail
ZM340
Type
TEX2
No current signal · last broadcast 16h ago
Flights observed
78
Distinct callsigns
20
Country
GB
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 43C921.

Country allocation

The ICAO 24-bit address 43C921 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 20 distinct

Callsign Airline Flights Last seen
VYT69 - 5 2026-05-21
RCKT1 - 5 2026-05-12
VYT88 - 4 2026-04-27
VYT76 - 4 2026-05-07
VYT71 - 4 2026-05-28
VYT74 - 3 2026-04-14
VYT60 - 3 2026-05-14
VYT572 - 3 2026-05-27
SWIFT1 - 3 2026-05-08
VYT96 - 2 2026-04-14
VYT94 - 2 2026-05-05
VYT91 - 2 2026-05-06
VYT89 - 2 2026-05-12
VYT85 - 2 2026-05-12
VYT84 - 2 2026-04-17
VYT79 - 2 2026-05-08
VYT61 - 2 2026-04-30
VYT589 - 2 2026-05-07
SWIFT02 - 2 2026-05-06
WINDR1 - 1 2026-04-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 RCKT01 - May 29, 07:30 UTCMay 29, 08:45 UTC1h 15m
2026-05-28 VYT71 - May 28, 10:15 UTCMay 28, 11:25 UTC1h 10m
2026-05-28 VYT80 - May 28, 07:50 UTCMay 28, 08:50 UTC1h 0m
2026-05-27 VYT572 - May 27, 07:50 UTCMay 27, 08:45 UTC55m
2026-05-26 WINDR02 - May 26, 15:20 UTCMay 26, 15:45 UTC25m
2026-05-26 VYT571 VLY → VLY May 26, 12:54 UTCMay 26, 13:50 UTC55m
2026-05-22 VYT55 - May 22, 14:40 UTCMay 22, 15:40 UTC1h 0m
2026-05-22 RCKT02 - May 22, 12:05 UTCMay 22, 13:10 UTC1h 5m
2026-05-22 VYT580 - May 22, 09:40 UTCMay 22, 10:45 UTC1h 5m
2026-05-22 VYT95 - May 22, 07:15 UTCMay 22, 08:00 UTC45m
2026-05-21 VYT92 - May 21, 12:35 UTCMay 21, 13:50 UTC1h 15m
2026-05-21 VYT69 - May 21, 10:25 UTCMay 21, 11:25 UTC1h 0m
2026-05-20 VYT69 - May 20, 15:05 UTCMay 20, 16:20 UTC1h 15m
2026-05-14 VYT60 VLY → VLY May 14, 07:10 UTCMay 14, 08:15 UTC1h 5m
2026-05-13 RCKT2 - May 13, 09:45 UTCMay 13, 10:20 UTC35m
2026-05-12 RCKT1 VLY → VLY May 12, 14:40 UTCMay 12, 15:55 UTC1h 15m
2026-05-12 VYT89 VLY → VLY May 12, 11:55 UTCMay 12, 12:55 UTC1h 0m
2026-05-12 VYT98 - May 12, 09:40 UTCMay 12, 10:30 UTC50m
2026-05-12 VYT85 VLY → VLY May 12, 07:15 UTCMay 12, 08:30 UTC1h 15m
2026-05-11 RCKT1 VLY → VLY May 11, 12:05 UTCMay 11, 13:30 UTC1h 25m
2026-05-11 VYT97 - May 11, 09:45 UTCMay 11, 10:40 UTC55m
2026-05-08 VYT71 - May 8, 12:49 UTCMay 8, 14:05 UTC1h 15m
2026-05-08 VYT79 - May 8, 10:19 UTCMay 8, 11:19 UTC1h 0m
2026-05-08 SWIFT1 - May 8, 07:34 UTCMay 8, 08:44 UTC1h 10m
2026-05-07 VYT75 VLY → VLY May 7, 15:15 UTCMay 7, 16:20 UTC1h 5m
2026-05-07 VYT76 - May 7, 12:40 UTCMay 7, 13:55 UTC1h 15m
2026-05-07 VYT589 - May 7, 10:00 UTCMay 7, 11:00 UTC1h 0m
2026-05-06 VYT81 - May 6, 14:45 UTCMay 6, 15:50 UTC1h 5m
2026-05-06 VYT91 - May 6, 12:30 UTCMay 6, 13:30 UTC1h 0m
2026-05-06 SWIFT02 - May 6, 10:30 UTCMay 6, 10:50 UTC20m
2026-05-06 VYT76 - May 6, 07:30 UTCMay 6, 08:10 UTC40m
2026-05-05 VYT94 - May 5, 12:50 UTCMay 5, 13:55 UTC1h 5m
2026-05-05 SWIFT1 - May 5, 10:10 UTCMay 5, 11:35 UTC1h 25m
2026-05-05 VYT94 VLY → VLY May 5, 07:35 UTCMay 5, 08:45 UTC1h 10m
2026-05-01 SWIFT02 - May 1, 14:55 UTCMay 1, 15:45 UTC50m
2026-05-01 SWIFT01 VLY → CEG May 1, 10:10 UTCMay 1, 11:35 UTC1h 25m
2026-04-30 VYT61 VLY → VLY Apr 30, 07:45 UTCApr 30, 08:45 UTC1h 0m
2026-04-29 VYT61 - Apr 29, 07:55 UTCApr 29, 09:05 UTC1h 11m
2026-04-28 VYT89 - Apr 28, 12:30 UTCApr 28, 13:30 UTC1h 0m
2026-04-28 VYT79 - Apr 28, 07:35 UTCApr 28, 08:15 UTC40m
2026-04-27 VYT87 VLY → VLY Apr 27, 15:45 UTCApr 27, 16:45 UTC1h 0m
2026-04-27 VYT88 - Apr 27, 12:55 UTCApr 27, 13:50 UTC55m
2026-04-27 VYT88 - Apr 27, 10:40 UTCApr 27, 11:30 UTC50m
2026-04-27 MTEOR1 - Apr 27, 07:50 UTCApr 27, 09:00 UTC1h 10m
2026-04-24 SWIFT1 - Apr 24, 14:10 UTCApr 24, 14:40 UTC30m
2026-04-24 VYT881 VLY → VLY Apr 24, 12:05 UTCApr 24, 12:35 UTC30m
2026-04-24 RCKT1 - Apr 24, 10:00 UTCApr 24, 10:30 UTC30m
2026-04-23 VYT69 - Apr 23, 11:30 UTCApr 23, 12:15 UTC45m
2026-04-23 VYT71 VLY → VLY Apr 23, 07:01 UTCApr 23, 08:05 UTC1h 5m
2026-04-22 RCKT1 - Apr 22, 14:35 UTCApr 22, 15:50 UTC1h 15m

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 ZM340 page for operator, model, and routing details .

Mode-S 43C921 frequently asked

What is Mode-S code 43C921?
43C921 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to ZM340.
Where is Mode-S 43C921 registered?
Mode-S code 43C921 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 43C921 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 43C921, octal 20744441, decimal 4,442,401.
What flights does 43C921 operate?
Mode-S 43C921 has broadcast 20 distinct callsigns, including VYT69, RCKT1, VYT88, VYT76, VYT71.