Apparatus

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sensors Mode-S transponder

781E51

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-32CF · AIRBUS A-321neo

Hex
781E51
Octal
36017121
Decimal
7,872,081
Country
CN
Tail
B-32CF
Type
A21N
No current signal · last broadcast Jul 26, 14:15 UTC
Flights observed
367
Distinct callsigns
20
Country
CN
Last broadcast
Jul 26, 14:15 UTC

Last known position

Most recent position reported by Mode-S 781E51.

Country allocation

The ICAO 24-bit address 781E51 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
CSZ9106 Shenzhen Airlines 29 2026-07-25
CSZ9074 Shenzhen Airlines 22 2026-07-26
CSZ9073 Shenzhen Airlines 22 2026-07-26
CSZ9114 Shenzhen Airlines 19 2026-07-25
CSZ9105 Shenzhen Airlines 18 2026-07-25
CSZ9113 Shenzhen Airlines 15 2026-07-26
CSZ9802 - 14 2026-07-05
CSZ9104 - 14 2026-07-20
CSZ9801 Shenzhen Airlines 13 2026-07-04
CSZ9110 Shenzhen Airlines 12 2026-07-23
CSZ9109 Shenzhen Airlines 11 2026-07-23
CSZ9506 Shenzhen Airlines 10 2026-07-24
CSZ9512 Shenzhen Airlines 8 2026-06-11
CSZ9505 Shenzhen Airlines 8 2026-07-24
CSZ9103 Shenzhen Airlines 8 2026-07-20
CSZ9209 - 7 2026-07-21
CSZ9102 - 6 2026-06-22
CSZ9403 Shenzhen Airlines 5 2026-07-23
CSZ9101 Shenzhen Airlines 5 2026-06-21
CSZ9948 - 4 2026-07-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 CSZ9113 SZX → PEK Jul 26, 14:05 UTCJul 26, 14:15 UTC10m
2026-07-26 CSZ9074 TPE → SZX Jul 26, 09:50 UTCJul 26, 11:25 UTC1h 35m
2026-07-26 CSZ9073 SZX → TPE Jul 26, 07:00 UTCJul 26, 08:20 UTC1h 20m
2026-07-25 CSZ9106 PEK → SZX Jul 25, 13:15 UTCJul 25, 13:35 UTC20m
2026-07-25 CSZ9106 PEK → SZX Jul 25, 10:35 UTCJul 25, 10:45 UTC10m
2026-07-25 CSZ9105 SZX → PEK Jul 25, 08:05 UTCJul 25, 08:20 UTC15m
2026-07-25 CSZ9114 PEK → SZX Jul 25, 03:00 UTCJul 25, 03:15 UTC15m
2026-07-25 CSZ9114 PEK → SZX Jul 25, 00:20 UTCJul 25, 01:05 UTC45m
2026-07-24 CSZ9113 SZX → PEK Jul 24, 15:35 UTCJul 24, 16:10 UTC35m
2026-07-24 CSZ9113 SZX → PEK Jul 24, 13:35 UTCJul 24, 13:45 UTC10m
2026-07-24 CSZ9506 PVG → SZX Jul 24, 11:50 UTCJul 24, 12:20 UTC30m
2026-07-24 CSZ9505 SZX → PVG Jul 24, 05:15 UTCJul 24, 05:25 UTC10m
2026-07-24 CSZ9854 NKG → SZX Jul 24, 03:25 UTCJul 24, 04:00 UTC35m
2026-07-23 CSZ9859 SZX → HGH Jul 23, 23:05 UTCJul 23, 23:15 UTC10m
2026-07-23 CSZ9110 PEK → SZX Jul 23, 16:00 UTCJul 23, 16:20 UTC20m
2026-07-23 CSZ9110 PEK → SZX Jul 23, 13:20 UTCJul 23, 13:40 UTC20m
2026-07-23 CSZ9109 SZX → PEK Jul 23, 10:55 UTCJul 23, 11:10 UTC15m
2026-07-23 CSZ9109 SZX → PEK Jul 23, 08:30 UTCJul 23, 08:45 UTC15m
2026-07-23 CSZ9403 SZX → CTU Jul 23, 01:00 UTCJul 23, 01:15 UTC15m
2026-07-22 CSZ9313 SZX → HAK Jul 22, 14:00 UTCJul 22, 14:15 UTC15m
2026-07-22 CSZ9106 - Jul 22, 12:40 UTCJul 22, 12:50 UTC10m
2026-07-21 CSZ9209 - Jul 21, 16:00 UTCJul 21, 16:10 UTC10m
2026-07-21 CSZ9506 PVG → SZX Jul 21, 13:45 UTCJul 21, 14:50 UTC1h 5m
2026-07-21 CSZ9505 - Jul 21, 07:40 UTCJul 21, 07:55 UTC15m
2026-07-20 CSZ9859 SZX → HGH Jul 20, 23:00 UTCJul 20, 23:10 UTC10m
2026-07-20 CSZ9948 - Jul 20, 16:50 UTCJul 20, 17:05 UTC15m
2026-07-20 CSZ9947 SZX → WUH Jul 20, 12:45 UTCJul 20, 12:55 UTC10m
2026-07-20 CSZ9104 - Jul 20, 11:15 UTCJul 20, 11:25 UTC10m
2026-07-20 CSZ9104 - Jul 20, 08:40 UTCJul 20, 08:55 UTC15m
2026-07-20 CSZ9103 SZX → PEK Jul 20, 02:20 UTCJul 20, 02:40 UTC20m
2026-07-19 CSZ9506 - Jul 19, 14:15 UTCJul 19, 14:30 UTC15m
2026-07-19 CSZ9114 PEK → SZX Jul 19, 00:05 UTCJul 19, 00:25 UTC20m
2026-07-18 CSZ9113 - Jul 18, 13:10 UTCJul 18, 13:20 UTC10m
2026-07-18 CSZ9104 - Jul 18, 10:55 UTCJul 18, 11:10 UTC15m
2026-07-18 CSZ9104 - Jul 18, 08:25 UTCJul 18, 08:40 UTC15m
2026-07-18 CSZ9103 SZX → PEK Jul 18, 04:50 UTCJul 18, 05:00 UTC10m
2026-07-18 CSZ9103 SZX → PEK Jul 18, 02:19 UTCJul 18, 02:35 UTC15m
2026-07-17 CSZ9468 - Jul 17, 16:59 UTCJul 17, 17:09 UTC10m
2026-07-17 CSZ9467 - Jul 17, 11:04 UTCJul 17, 11:20 UTC15m
2026-07-17 CSZ9104 - Jul 17, 09:25 UTCJul 17, 09:40 UTC15m
2026-07-17 CSZ9104 - Jul 17, 06:54 UTCJul 17, 07:05 UTC10m
2026-07-17 CSZ9103 - Jul 17, 02:15 UTCJul 17, 02:30 UTC15m
2026-07-16 CSZ9948 - Jul 16, 15:35 UTCJul 16, 16:00 UTC25m
2026-07-16 CSZ9947 - Jul 16, 10:40 UTCJul 16, 10:50 UTC10m
2026-07-16 CSZ9930 - Jul 16, 09:10 UTCJul 16, 09:20 UTC10m
2026-07-16 CSZ9929 - Jul 16, 01:30 UTCJul 16, 01:40 UTC10m
2026-07-15 CSZ9108 - Jul 15, 14:05 UTCJul 15, 14:20 UTC15m
2026-07-15 CSZ9108 - Jul 15, 11:40 UTCJul 15, 11:55 UTC15m
2026-07-15 CSZ9107 - Jul 15, 09:20 UTCJul 15, 09:30 UTC10m
2026-07-15 CSZ9107 - Jul 15, 06:50 UTCJul 15, 07:00 UTC10m

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-32CF page for operator, model, and routing details .

Mode-S 781E51 frequently asked

What is Mode-S code 781E51?
781E51 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-32CF.
Where is Mode-S 781E51 registered?
Mode-S code 781E51 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 781E51 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 14:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 781E51, octal 36017121, decimal 7,872,081.
What flights does 781E51 operate?
Mode-S 781E51 has broadcast 20 distinct callsigns, including CSZ9106, CSZ9074, CSZ9073, CSZ9114, CSZ9105.