sensors Mode-S transponder

7C41D9

ICAO 24-bit transponder address · allocated to Australia

Currently assigned to VH-NAJ · BEECHCRAFT Super King Air 350 · operated by ROYAL FLYING DOCTOR SERVICE OF AUSTRALIA (SOUTH EASTERN SECTION)

Hex
7C41D9
Octal
37040731
Decimal
8,143,321
Country
AU
Tail
VH-NAJ
Type
B350
No current signal · last broadcast 1d ago
Flights observed
95
Distinct callsigns
8
Country
AU
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 7C41D9.

Country allocation

The ICAO 24-bit address 7C41D9 falls within the block assigned to Australia (AU) by ICAO Annex 10, Volume III. Every aircraft registered in Australia 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 8 distinct

Callsign Airline Flights Last seen
FD264 - 21 2026-05-12
FD257 - 19 2026-05-06
FD229 - 19 2026-05-29
FD291 - 15 2026-05-29
FD231 Thai AirAsia 9 2026-05-20
FD214 - 6 2026-05-19
FD227 - 5 2026-05-14
FD258 - 1 2026-05-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 FD291 - May 29, 08:25 UTCMay 29, 09:05 UTC40m
2026-05-29 FD291 MEB → ABX May 29, 07:20 UTCMay 29, 08:00 UTC40m
2026-05-29 FD229 - May 29, 02:35 UTCMay 29, 03:10 UTC35m
2026-05-28 FD229 - May 28, 23:25 UTCMay 29, 00:05 UTC40m
2026-05-28 FD291 - May 28, 06:45 UTCMay 28, 07:15 UTC30m
2026-05-28 FD291 - May 28, 05:30 UTCMay 28, 05:50 UTC20m
2026-05-27 FD291 - May 27, 09:05 UTCMay 27, 09:50 UTC45m
2026-05-27 FD291 - May 27, 07:40 UTCMay 27, 08:15 UTC35m
2026-05-26 FD291 - May 26, 07:15 UTCMay 26, 07:59 UTC45m
2026-05-26 FD291 - May 26, 05:10 UTCMay 26, 05:49 UTC40m
2026-05-26 FD229 - May 26, 04:00 UTCMay 26, 04:24 UTC25m
2026-05-26 FD229 - May 26, 02:49 UTCMay 26, 03:15 UTC25m
2026-05-26 FD229 - May 26, 01:00 UTCMay 26, 01:24 UTC25m
2026-05-25 FD229 - May 25, 23:24 UTCMay 25, 23:49 UTC25m
2026-05-25 FD291 - May 25, 07:50 UTCMay 25, 08:10 UTC20m
2026-05-25 FD291 - May 25, 05:55 UTCMay 25, 06:20 UTC25m
2026-05-25 FD229 - May 25, 03:55 UTCMay 25, 04:10 UTC15m
2026-05-25 FD229 - May 25, 02:45 UTCMay 25, 03:20 UTC35m
2026-05-24 FD229 - May 24, 23:00 UTCMay 24, 23:46 UTC46m
2026-05-22 FD258 BWU → MEB May 22, 01:10 UTCMay 22, 02:55 UTC1h 45m
2026-05-20 FD231 TPE → DMK May 20, 08:25 UTCMay 20, 09:05 UTC40m
2026-05-20 FD231 TPE → DMK May 20, 05:00 UTCMay 20, 05:30 UTC30m
2026-05-19 FD214 - May 19, 05:40 UTCMay 19, 06:15 UTC35m
2026-05-19 FD214 - May 19, 04:05 UTCMay 19, 04:40 UTC35m
2026-05-15 FD231 TPE → DMK May 15, 09:25 UTCMay 15, 10:00 UTC35m
2026-05-15 FD231 TPE → DMK May 15, 07:55 UTCMay 15, 08:30 UTC35m
2026-05-15 FD231 TPE → DMK May 15, 06:45 UTCMay 15, 07:20 UTC35m
2026-05-15 FD231 TPE → DMK May 15, 03:20 UTCMay 15, 04:05 UTC45m
2026-05-14 FD227 - May 14, 08:30 UTCMay 14, 09:15 UTC45m
2026-05-14 FD227 - May 14, 04:35 UTCMay 14, 06:15 UTC1h 40m
2026-05-14 FD227 - May 14, 02:15 UTCMay 14, 02:45 UTC30m
2026-05-13 FD214 - May 13, 08:25 UTCMay 13, 08:55 UTC30m
2026-05-13 FD214 - May 13, 02:20 UTCMay 13, 02:40 UTC20m
2026-05-12 FD264 - May 12, 08:40 UTCMay 12, 09:15 UTC35m
2026-05-12 FD264 - May 12, 05:50 UTCMay 12, 06:00 UTC10m
2026-05-12 FD264 - May 12, 03:30 UTCMay 12, 04:30 UTC1h 0m
2026-05-11 FD214 - May 11, 07:25 UTCMay 11, 07:50 UTC25m
2026-05-11 FD214 - May 11, 05:10 UTCMay 11, 05:35 UTC25m
2026-05-08 FD264 - May 8, 09:14 UTCMay 8, 09:39 UTC25m
2026-05-08 FD264 - May 8, 06:04 UTCMay 8, 07:29 UTC1h 25m
2026-05-08 FD264 - May 8, 04:25 UTCMay 8, 05:05 UTC40m
2026-05-08 FD264 - May 8, 02:39 UTCMay 8, 03:30 UTC50m
2026-05-07 FD264 - May 7, 09:35 UTCMay 7, 10:00 UTC25m
2026-05-07 FD264 - May 7, 08:00 UTCMay 7, 08:10 UTC10m
2026-05-07 FD264 - May 7, 06:10 UTCMay 7, 06:40 UTC30m
2026-05-07 FD264 - May 7, 04:50 UTCMay 7, 05:25 UTC35m
2026-05-07 FD264 - May 7, 02:15 UTCMay 7, 02:50 UTC35m
2026-05-06 FD257 - May 6, 09:20 UTCMay 6, 09:55 UTC35m
2026-05-06 FD257 - May 6, 06:30 UTCMay 6, 07:05 UTC35m
2026-05-06 FD257 - May 6, 04:20 UTCMay 6, 04:50 UTC30m

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 VH-NAJ page for operator, model, and routing details .

Mode-S 7C41D9 frequently asked

What is Mode-S code 7C41D9?
7C41D9 is an ICAO 24-bit transponder address. Allocated to Australia. Assigned to VH-NAJ.
Where is Mode-S 7C41D9 registered?
Mode-S code 7C41D9 is allocated to Australia (AU). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7C41D9 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 7C41D9, octal 37040731, decimal 8,143,321.
What flights does 7C41D9 operate?
Mode-S 7C41D9 has broadcast 8 distinct callsigns, including FD264, FD257, FD229, FD291, FD231.