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sensors Mode-S transponder

78921B

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-HNS · BOEING 777-300

Hex
78921B
Octal
36111033
Decimal
7,901,723
Country
CN
Tail
B-HNS
Type
B773
No current signal · last broadcast Jul 25, 13:30 UTC
Flights observed
402
Distinct callsigns
20
Country
CN
Last broadcast
Jul 25, 13:30 UTC

Last known position

Most recent position reported by Mode-S 78921B.

Country allocation

The ICAO 24-bit address 78921B falls within the block assigned to China (CN) by ICAO Annex 10, Volume III. Every aircraft registered in China 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
CPA521 - 22 2026-07-17
CPA918 Cathay Pacific 19 2026-07-23
CPA450 - 17 2026-07-03
CPA919 Cathay Pacific 15 2026-07-23
CPA785 Cathay Pacific 15 2026-07-25
CPA565 Cathay Pacific 15 2026-05-31
CPA451 - 15 2026-07-18
CPA974 - 14 2026-07-10
CPA798 Cathay Pacific 13 2026-07-24
CPA520 - 13 2026-07-17
CPA507 - 13 2026-07-06
CPA913 - 12 2026-07-10
CPA361 Cathay Pacific 12 2026-07-19
CPA505 - 11 2026-07-03
CPA784 Cathay Pacific 10 2026-07-25
CPA797 Cathay Pacific 9 2026-07-24
CPA506 - 9 2026-07-06
CPA411 Cathay Pacific 9 2026-07-24
CPA362 - 9 2026-06-30
CPA930 - 8 2026-07-07

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 CPA784 DPS → HKG Jul 25, 12:55 UTCJul 25, 13:10 UTC15m
2026-07-25 CPA785 HKG → DPS Jul 25, 04:30 UTCJul 25, 10:50 UTC6h 20m
2026-07-25 CPA785 HKG → DPS Jul 25, 02:30 UTCJul 25, 02:50 UTC20m
2026-07-24 CPA798 CGK → HKG Jul 24, 21:25 UTCJul 24, 21:45 UTC20m
2026-07-24 CPA798 CGK → HKG Jul 24, 17:30 UTCJul 24, 18:50 UTC1h 20m
2026-07-24 CPA797 HKG → CGK Jul 24, 15:25 UTCJul 24, 15:45 UTC20m
2026-07-24 CPA797 HKG → CGK Jul 24, 11:35 UTCJul 24, 11:50 UTC15m
2026-07-24 CPA411 ICN → HKG Jul 24, 06:30 UTCJul 24, 09:30 UTC3h 0m
2026-07-24 CPA410 HKG → ICN Jul 24, 01:50 UTCJul 24, 05:00 UTC3h 10m
2026-07-23 CPA918 MNL → HKG Jul 23, 10:40 UTCJul 23, 12:15 UTC1h 35m
2026-07-23 CPA919 HKG → MNL Jul 23, 07:05 UTCJul 23, 08:45 UTC1h 40m
2026-07-23 CPA543 HND → HKG Jul 23, 01:40 UTCJul 23, 05:10 UTC3h 30m
2026-07-22 CPA542 HKG → HND Jul 22, 11:15 UTCJul 22, 12:25 UTC1h 10m
2026-07-22 CPA970 HKG → XMN Jul 22, 02:05 UTCJul 22, 02:20 UTC15m
2026-07-21 CPA918 MNL → HKG Jul 21, 12:50 UTCJul 21, 13:05 UTC15m
2026-07-21 CPA918 MNL → HKG Jul 21, 11:30 UTCJul 21, 12:00 UTC30m
2026-07-21 CPA919 HKG → MNL Jul 21, 06:25 UTCJul 21, 08:15 UTC1h 50m
2026-07-20 CPA302 HKG → HKG Jul 20, 13:40 UTCJul 21, 01:35 UTC11h 54m
2026-07-20 CPA918 - Jul 20, 10:00 UTCJul 20, 11:40 UTC1h 40m
2026-07-20 CPA919 HKG → MNL Jul 20, 06:30 UTCJul 20, 08:15 UTC1h 45m
2026-07-19 CPA361 PVG → HKG Jul 19, 15:20 UTCJul 20, 03:25 UTC12h 5m
2026-07-19 CPA784 - Jul 19, 12:40 UTCJul 19, 13:20 UTC40m
2026-07-19 CPA785 HKG → DPS Jul 19, 02:40 UTCJul 19, 10:45 UTC8h 5m
2026-07-18 CPA451 TPE → HKG Jul 18, 11:35 UTCJul 18, 12:50 UTC1h 15m
2026-07-18 CPA451 - Jul 18, 09:35 UTCJul 18, 09:50 UTC15m
2026-07-18 CPA451 - Jul 18, 07:05 UTCJul 18, 08:20 UTC1h 15m
2026-07-18 CPA504 HKG → NRT Jul 18, 01:25 UTCJul 18, 05:25 UTC4h 1m
2026-07-17 CPA521 NRT → HKG Jul 17, 11:35 UTCJul 17, 15:20 UTC3h 45m
2026-07-17 CPA520 HKG → NRT Jul 17, 05:35 UTCJul 17, 09:55 UTC4h 20m
2026-07-16 CPA918 MNL → HKG Jul 16, 12:40 UTCJul 16, 14:20 UTC1h 40m
2026-07-16 CPA919 - Jul 16, 09:20 UTCJul 16, 11:05 UTC1h 45m
2026-07-16 CPA766 - Jul 16, 06:45 UTCJul 16, 07:10 UTC25m
2026-07-16 CPA767 - Jul 16, 01:10 UTCJul 16, 01:25 UTC15m
2026-07-15 CPA764 - Jul 15, 15:55 UTCJul 15, 16:15 UTC20m
2026-07-15 CPA769 - Jul 15, 10:10 UTCJul 15, 10:25 UTC15m
2026-07-15 CPA431 KHH → HKG Jul 15, 03:20 UTCJul 15, 04:25 UTC1h 5m
2026-07-15 CPA432 HKG → KHH Jul 15, 00:55 UTCJul 15, 02:00 UTC1h 5m
2026-07-14 CPA451 TPE → HKG Jul 14, 11:40 UTCJul 14, 13:00 UTC1h 20m
2026-07-14 CPA451 NRT → TPE Jul 14, 07:40 UTCJul 14, 10:25 UTC2h 45m
2026-07-14 CPA504 - Jul 14, 01:45 UTCJul 14, 05:45 UTC4h 0m
2026-07-13 CPA918 - Jul 13, 11:55 UTCJul 13, 12:10 UTC15m
2026-07-13 CPA918 - Jul 13, 10:35 UTCJul 13, 11:00 UTC25m
2026-07-13 CPA919 - Jul 13, 07:40 UTCJul 13, 08:15 UTC35m
2026-07-13 CPA919 - Jul 13, 06:30 UTCJul 13, 06:45 UTC15m
2026-07-13 CPA431 KHH → HKG Jul 13, 03:30 UTCJul 13, 04:30 UTC1h 0m
2026-07-13 CPA432 HKG → KHH Jul 13, 00:55 UTCJul 13, 02:01 UTC1h 5m
2026-07-12 CPA411 ICN → HKG Jul 12, 07:10 UTCJul 12, 10:05 UTC2h 55m
2026-07-12 CPA410 - Jul 12, 03:01 UTCJul 12, 05:15 UTC2h 15m
2026-07-12 CPA410 - Jul 12, 02:10 UTCJul 12, 02:25 UTC15m
2026-07-11 CPA798 - Jul 11, 21:50 UTCJul 11, 22:20 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 B-HNS page for operator, model, and routing details .

Mode-S 78921B frequently asked

What is Mode-S code 78921B?
78921B is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-HNS.
Where is Mode-S 78921B registered?
Mode-S code 78921B is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 78921B broadcasting right now?
No active broadcast right now. Last signal was Jul 25, 13:30 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 78921B, octal 36111033, decimal 7,901,723.
What flights does 78921B operate?
Mode-S 78921B has broadcast 20 distinct callsigns, including CPA521, CPA918, CPA450, CPA919, CPA785.