sensors Mode-S transponder

7801B9

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-HYQ · AIRBUS A-330-300

Hex
7801B9
Octal
36000671
Decimal
7,864,761
Country
CN
Tail
B-HYQ
Type
A333
No current signal · last broadcast 14h ago
Flights observed
11
Distinct callsigns
6
Country
CN
Last broadcast
14h ago

Last known position

Most recent position reported by Mode-S 7801B9.

Country allocation

The ICAO 24-bit address 7801B9 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 6 distinct

Callsign Airline Flights Last seen
CPA758 Cathay Pacific 2 2026-04-14
CPA715 - 2 2026-04-13
CPA714 - 2 2026-04-13
CPA654 - 2 2026-04-13
CPA653 - 2 2026-04-13
CPA345 Cathay Pacific 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 CPA758 SIN → HKG Apr 14, 09:30 UTCApr 14, 10:00 UTC30m
2026-04-14 CPA758 SIN → HKG Apr 14, 06:10 UTCApr 14, 06:55 UTC45m
2026-04-13 CPA714 - Apr 13, 21:55 UTCApr 13, 22:10 UTC15m
2026-04-13 CPA714 - Apr 13, 18:55 UTCApr 13, 19:10 UTC15m
2026-04-13 CPA715 - Apr 13, 16:20 UTCApr 13, 16:45 UTC25m
2026-04-13 CPA715 - Apr 13, 13:25 UTCApr 13, 13:40 UTC15m
2026-04-13 CPA654 - Apr 13, 10:45 UTCApr 13, 11:05 UTC20m
2026-04-13 CPA654 - Apr 13, 08:40 UTCApr 13, 08:55 UTC15m
2026-04-13 CPA653 - Apr 13, 06:40 UTCApr 13, 06:50 UTC10m
2026-04-13 CPA653 - Apr 13, 04:25 UTCApr 13, 04:40 UTC15m
2026-04-13 CPA345 PEK → HKG Apr 13, 02:20 UTCApr 13, 02:50 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 B-HYQ page for operator, model, and routing details .

Mode-S 7801B9 frequently asked

What is Mode-S code 7801B9?
7801B9 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-HYQ.
Where is Mode-S 7801B9 registered?
Mode-S code 7801B9 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7801B9 broadcasting right now?
No active broadcast right now. Last signal was 14h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 7801B9, octal 36000671, decimal 7,864,761.
What flights does 7801B9 operate?
Mode-S 7801B9 has broadcast 6 distinct callsigns, including CPA758, CPA715, CPA714, CPA654, CPA653.