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sensors Mode-S transponder

781D8E

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-221U · BOEING 757-200

Hex
781D8E
Octal
36016616
Decimal
7,871,886
Country
CN
Tail
B-221U
Type
B752
No current signal · last broadcast 8h ago
Flights observed
119
Distinct callsigns
20
Country
CN
Last broadcast
8h ago

Last known position

Most recent position reported by Mode-S 781D8E.

Country allocation

The ICAO 24-bit address 781D8E 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
CSS326 - 12 2026-07-09
CSS6811 - 7 2026-07-10
CSS314 - 7 2026-07-09
CSS313 - 7 2026-07-09
CSS7344 - 6 2026-07-02
CSS325 - 6 2026-07-09
CSS6839 - 5 2026-07-17
CSS6840 - 4 2026-07-16
CSS7277 - 3 2026-07-17
CSS7240 - 3 2026-07-05
CSS7125 SF Airlines 3 2026-05-27
CSS6846 SF Airlines 3 2026-06-16
CSS6812 - 3 2026-07-07
CSS280 - 3 2026-06-22
CSS279 - 3 2026-06-22
CSS142 - 3 2026-06-22
CSS141 - 3 2026-06-20
CSS7278 - 2 2026-07-16
CSS7202 - 2 2026-06-25
CSS7109 SF Airlines 2 2026-06-10

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 CSS6839 - Jul 17, 22:20 UTCJul 17, 22:29 UTC10m
2026-07-17 CSS7277 - Jul 17, 19:25 UTCJul 17, 19:35 UTC10m
2026-07-16 CSS7278 - Jul 16, 20:55 UTCJul 16, 21:05 UTC10m
2026-07-16 CSS6840 - Jul 16, 18:44 UTCJul 16, 19:05 UTC20m
2026-07-15 CSS6839 - Jul 15, 22:20 UTCJul 15, 22:30 UTC10m
2026-07-14 CSS727S - Jul 14, 19:15 UTCJul 14, 19:55 UTC40m
2026-07-10 CSS6811 - Jul 10, 17:40 UTCJul 10, 17:55 UTC15m
2026-07-09 CSS326 - Jul 9, 23:45 UTCJul 10, 00:20 UTC35m
2026-07-09 CSS326 - Jul 9, 22:25 UTCJul 9, 22:55 UTC30m
2026-07-09 CSS325 - Jul 9, 18:40 UTCJul 9, 20:30 UTC1h 50m
2026-07-09 CSS314 - Jul 9, 14:15 UTCJul 9, 14:30 UTC15m
2026-07-09 CSS314 - Jul 9, 12:05 UTCJul 9, 12:35 UTC30m
2026-07-09 CSS313 - Jul 9, 09:05 UTCJul 9, 09:35 UTC30m
2026-07-09 CSS313 - Jul 9, 07:20 UTCJul 9, 07:30 UTC10m
2026-07-08 CSS7107 - Jul 8, 00:40 UTCJul 8, 00:50 UTC10m
2026-07-07 CSS7107 - Jul 7, 22:00 UTCJul 7, 22:20 UTC20m
2026-07-07 CSS6811 - Jul 7, 20:15 UTCJul 7, 20:25 UTC10m
2026-07-07 CSS6811 - Jul 7, 17:50 UTCJul 7, 18:05 UTC15m
2026-07-07 CSS6812 - Jul 7, 00:00 UTCJul 7, 00:25 UTC25m
2026-07-06 CSS6812 - Jul 6, 20:40 UTCJul 6, 21:00 UTC20m
2026-07-05 CSS7240 - Jul 5, 20:55 UTCJul 5, 21:05 UTC10m
2026-07-04 CSS7240 - Jul 4, 22:05 UTCJul 4, 22:15 UTC10m
2026-07-04 CSS7120 - Jul 4, 20:25 UTCJul 4, 20:40 UTC15m
2026-07-03 CSS7240 - Jul 3, 20:45 UTCJul 3, 20:55 UTC10m
2026-07-02 CSS7344 - Jul 2, 21:50 UTCJul 2, 22:00 UTC10m
2026-07-01 CSS7344 - Jul 1, 21:40 UTCJul 1, 21:50 UTC10m
2026-07-01 CSS6811 - Jul 1, 17:00 UTCJul 1, 17:15 UTC15m
2026-06-30 CSS6828 PVG → SZX Jun 30, 22:25 UTCJun 30, 22:45 UTC20m
2026-06-30 CSS6827 - Jun 30, 17:20 UTCJun 30, 17:30 UTC10m
2026-06-29 CSS6802 - Jun 29, 20:54 UTCJun 29, 21:09 UTC15m
2026-06-26 CSS3068 - Jun 26, 20:24 UTCJun 26, 20:44 UTC20m
2026-06-25 CSS7202 - Jun 25, 21:55 UTCJun 25, 22:10 UTC15m
2026-06-24 CSS7686 - Jun 24, 23:00 UTCJun 24, 23:10 UTC10m
2026-06-22 CSS142 - Jun 22, 14:55 UTCJun 22, 15:20 UTC25m
2026-06-22 CSS279 - Jun 22, 05:49 UTCJun 22, 06:15 UTC25m
2026-06-22 CSS280 - Jun 22, 02:54 UTCJun 22, 03:14 UTC20m
2026-06-20 CSS141 - Jun 20, 22:59 UTCJun 20, 23:25 UTC25m
2026-06-18 CSS142 ICN → EHU Jun 18, 14:45 UTCJun 18, 15:05 UTC20m
2026-06-18 CSS279 - Jun 18, 05:50 UTCJun 18, 06:15 UTC25m
2026-06-18 CSS280 - Jun 18, 02:50 UTCJun 18, 03:05 UTC15m
2026-06-17 CSS141 - Jun 17, 23:30 UTCJun 17, 23:50 UTC20m
2026-06-16 CSS6936 - Jun 16, 16:00 UTCJun 16, 16:10 UTC10m
2026-06-16 CSS6846 NTG → SZX Jun 16, 01:35 UTCJun 16, 02:00 UTC25m
2026-06-15 CSS6845 SZX → NTG Jun 15, 20:54 UTCJun 15, 21:04 UTC10m
2026-06-15 CSS6834 - Jun 15, 17:59 UTCJun 15, 18:45 UTC45m
2026-06-15 CSS7250 - Jun 15, 13:00 UTCJun 15, 13:10 UTC10m
2026-06-14 CSS6813 - Jun 14, 18:55 UTCJun 14, 19:10 UTC15m
2026-06-13 CSS326 MNL → SZX Jun 13, 22:15 UTCJun 13, 22:30 UTC15m
2026-06-13 CSS326 MNL → SZX Jun 13, 20:30 UTCJun 13, 21:05 UTC35m
2026-06-13 CSS325 - Jun 13, 16:30 UTCJun 13, 18:30 UTC2h 0m

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-221U page for operator, model, and routing details .

Mode-S 781D8E frequently asked

What is Mode-S code 781D8E?
781D8E is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-221U.
Where is Mode-S 781D8E registered?
Mode-S code 781D8E is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 781D8E broadcasting right now?
No active broadcast right now. Last signal was 8h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 781D8E, octal 36016616, decimal 7,871,886.
What flights does 781D8E operate?
Mode-S 781D8E has broadcast 20 distinct callsigns, including CSS326, CSS6811, CSS314, CSS313, CSS7344.