Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

78921C

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-HNU · BOEING 777-300

Hex
78921C
Octal
36111034
Decimal
7,901,724
Country
CN
Tail
B-HNU
Type
B773
Broadcasting now · callsign CPA411 · 34,000 ft
Flights observed
273
Distinct callsigns
20
Country
CN
Last broadcast
Jul 26, 20:55 UTC

Current position

78921C is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 78921C 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
CPA718 Cathay Pacific 17 2026-07-23
CPA450 Cathay Pacific 17 2026-07-25
CPA798 Cathay Pacific 14 2026-07-26
CPA719 Cathay Pacific 14 2026-07-22
CPA520 - 13 2026-07-13
CPA797 Cathay Pacific 11 2026-07-26
CPA521 - 11 2026-07-13
CPA565 - 10 2026-07-18
CPA507 - 10 2026-07-14
CPA451 Cathay Pacific 10 2026-05-11
CPA564 Cathay Pacific 9 2026-07-18
CPA543 Cathay Pacific 9 2026-07-20
CPA506 - 8 2026-07-14
CPA542 Cathay Pacific 7 2026-07-19
CPA505 Cathay Pacific 7 2026-07-25
CPA784 Cathay Pacific 6 2026-06-07
CPA785 Cathay Pacific 5 2026-06-07
CPA764 Cathay Pacific 5 2026-05-31
CPA504 Cathay Pacific 5 2026-05-11
CPA901 - 4 2026-07-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 CPA798 CGK → HKG Jul 26, 19:30 UTCJul 26, 20:55 UTC1h 25m
2026-07-26 CPA797 HKG → CGK Jul 26, 16:45 UTCJul 26, 17:10 UTC25m
2026-07-26 CPA797 HKG → CGK Jul 26, 12:55 UTCJul 26, 13:05 UTC10m
2026-07-25 CPA505 NRT → HKG Jul 25, 11:05 UTCJul 25, 14:55 UTC3h 50m
2026-07-25 CPA450 HKG → TPE Jul 25, 07:55 UTCJul 25, 09:10 UTC1h 15m
2026-07-25 CPA450 HKG → TPE Jul 25, 06:25 UTCJul 25, 06:35 UTC10m
2026-07-25 CPA450 HKG → TPE Jul 25, 03:25 UTCJul 25, 04:50 UTC1h 25m
2026-07-24 CPA505 NRT → HKG Jul 24, 10:00 UTCJul 24, 13:45 UTC3h 45m
2026-07-24 CPA450 HKG → TPE Jul 24, 06:45 UTCJul 24, 08:05 UTC1h 20m
2026-07-24 CPA450 HKG → TPE Jul 24, 05:15 UTCJul 24, 05:30 UTC15m
2026-07-24 CPA450 HKG → TPE Jul 24, 02:10 UTCJul 24, 03:35 UTC1h 25m
2026-07-23 CPA769 HKG → SGN Jul 23, 07:55 UTCJul 23, 08:10 UTC15m
2026-07-23 CPA718 CGK → HKG Jul 23, 05:30 UTCJul 23, 05:55 UTC25m
2026-07-23 CPA718 CGK → HKG Jul 23, 02:55 UTCJul 23, 03:50 UTC55m
2026-07-23 CPA718 CGK → HKG Jul 23, 01:15 UTCJul 23, 01:25 UTC10m
2026-07-22 CPA719 HKG → CGK Jul 22, 12:15 UTCJul 22, 12:30 UTC15m
2026-07-22 CPA718 CGK → HKG Jul 22, 04:55 UTCJul 22, 05:20 UTC25m
2026-07-22 CPA718 CGK → HKG Jul 22, 02:50 UTCJul 22, 03:20 UTC30m
2026-07-21 CPA719 HKG → CGK Jul 21, 12:05 UTCJul 21, 12:20 UTC15m
2026-07-21 CPA719 HKG → CGK Jul 21, 08:10 UTCJul 21, 08:25 UTC15m
2026-07-21 CPA718 CGK → HKG Jul 21, 05:05 UTCJul 21, 05:30 UTC25m
2026-07-21 CPA718 CGK → HKG Jul 21, 02:55 UTCJul 21, 03:30 UTC35m
2026-07-20 CPA719 - Jul 20, 12:35 UTCJul 20, 12:55 UTC20m
2026-07-20 CPA719 - Jul 20, 08:50 UTCJul 20, 09:05 UTC15m
2026-07-20 CPA543 HND → HKG Jul 20, 01:40 UTCJul 20, 05:30 UTC3h 50m
2026-07-19 CPA542 HKG → HND Jul 19, 08:40 UTCJul 19, 12:30 UTC3h 50m
2026-07-19 CPA431 KHH → HKG Jul 19, 03:30 UTCJul 19, 04:40 UTC1h 10m
2026-07-19 CPA431 KHH → HKG Jul 19, 03:15 UTCJul 19, 03:20 UTC5m
2026-07-19 CPA432 HKG → KHH Jul 19, 00:50 UTCJul 19, 02:05 UTC1h 15m
2026-07-18 CPA565 - Jul 18, 11:30 UTCJul 18, 12:45 UTC1h 15m
2026-07-18 CPA565 - Jul 18, 09:40 UTCJul 18, 09:55 UTC15m
2026-07-18 CPA565 - Jul 18, 07:45 UTCJul 18, 08:25 UTC40m
2026-07-18 CPA564 HKG → TPE Jul 18, 05:25 UTCJul 18, 06:10 UTC45m
2026-07-18 CPA564 HKG → TPE Jul 18, 03:50 UTCJul 18, 04:05 UTC15m
2026-07-18 CPA564 HKG → TPE Jul 18, 00:45 UTCJul 18, 02:14 UTC1h 30m
2026-07-17 CPA505 NRT → HKG Jul 17, 10:15 UTCJul 17, 13:55 UTC3h 40m
2026-07-17 CPA450 HKG → TPE Jul 17, 07:05 UTCJul 17, 08:30 UTC1h 25m
2026-07-17 CPA450 HKG → TPE Jul 17, 05:30 UTCJul 17, 05:45 UTC15m
2026-07-17 CPA450 HKG → TPE Jul 17, 02:39 UTCJul 17, 04:10 UTC1h 30m
2026-07-16 CPA974 - Jul 16, 21:40 UTCJul 16, 23:20 UTC1h 40m
2026-07-16 CPA913 HKG → MNL Jul 16, 14:15 UTCJul 16, 16:05 UTC1h 50m
2026-07-16 CPA421 TPE → HKG Jul 16, 10:40 UTCJul 16, 11:54 UTC1h 15m
2026-07-16 CPA420 HKG → TPE Jul 16, 07:30 UTCJul 16, 09:10 UTC1h 40m
2026-07-16 CPA489 TPE → HKG Jul 16, 03:55 UTCJul 16, 05:35 UTC1h 40m
2026-07-16 CPA488 HKG → TPE Jul 16, 00:50 UTCJul 16, 02:15 UTC1h 25m
2026-07-15 CPA798 - Jul 15, 22:10 UTCJul 15, 22:40 UTC30m
2026-07-15 CPA798 - Jul 15, 18:05 UTCJul 15, 19:25 UTC1h 20m
2026-07-15 CPA797 - Jul 15, 15:45 UTCJul 15, 16:00 UTC15m
2026-07-15 CPA797 - Jul 15, 12:00 UTCJul 15, 12:15 UTC15m
2026-07-15 CPA930 - Jul 15, 04:55 UTCJul 15, 06:50 UTC1h 55m

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-HNU page for operator, model, and routing details .

Mode-S 78921C frequently asked

What is Mode-S code 78921C?
78921C is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-HNU.
Where is Mode-S 78921C registered?
Mode-S code 78921C is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 78921C broadcasting right now?
Yes. Mode-S 78921C is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 78921C, octal 36111034, decimal 7,901,724.
What flights does 78921C operate?
Mode-S 78921C has broadcast 20 distinct callsigns, including CPA718, CPA450, CPA798, CPA719, CPA520.