Apparatus

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sensors Mode-S transponder

781DC7

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-221Y · BOEING 777-200LR

Hex
781DC7
Octal
36016707
Decimal
7,871,943
Country
CN
Tail
B-221Y
Type
B77L
No current signal · last broadcast 5h ago
Flights observed
134
Distinct callsigns
7
Country
CN
Last broadcast
5h ago

Last known position

Most recent position reported by Mode-S 781DC7.

Country allocation

The ICAO 24-bit address 781DC7 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 7 distinct

Callsign Airline Flights Last seen
CYZ257 - 53 2026-07-11
CYZ258 - 17 2026-07-09
CYZ256 China Postal Airlines 17 2026-05-13
CYZ255 China Postal Airlines 17 2026-05-14
CYZ294 - 12 2026-07-08
CYZ278 - 9 2026-07-11
CYZ237 - 9 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 CYZ237 - Jul 14, 03:15 UTCJul 14, 09:40 UTC6h 25m
2026-07-11 CYZ278 - Jul 11, 10:55 UTCJul 11, 17:15 UTC6h 20m
2026-07-11 CYZ257 - Jul 11, 00:40 UTCJul 11, 07:00 UTC6h 20m
2026-07-09 CYZ258 - Jul 9, 11:20 UTCJul 9, 17:35 UTC6h 15m
2026-07-08 CYZ257 - Jul 8, 11:15 UTCJul 9, 07:05 UTC19h 50m
2026-07-08 CYZ257 - Jul 8, 07:50 UTCJul 9, 07:05 UTC23h 15m
2026-07-08 CYZ294 - Jul 8, 05:50 UTCJul 9, 05:45 UTC23h 55m
2026-07-08 CYZ294 - Jul 8, 05:35 UTCJul 9, 03:45 UTC22h 10m
2026-07-07 CYZ237 - Jul 7, 03:15 UTCJul 7, 09:40 UTC6h 25m
2026-07-04 CYZ278 - Jul 4, 11:10 UTCJul 4, 17:20 UTC6h 10m
2026-07-04 CYZ257 - Jul 4, 00:50 UTCJul 4, 07:25 UTC6h 35m
2026-07-02 CYZ258 - Jul 2, 10:55 UTCJul 2, 16:45 UTC5h 50m
2026-07-02 CYZ257 - Jul 2, 07:10 UTCJul 2, 07:45 UTC35m
2026-07-01 CYZ257 - Jul 1, 11:00 UTCJul 2, 04:30 UTC17h 30m
2026-07-01 CYZ257 - Jul 1, 07:50 UTCJul 2, 04:30 UTC20h 40m
2026-07-01 CYZ294 - Jul 1, 05:50 UTCJul 2, 04:30 UTC22h 40m
2026-07-01 CYZ294 - Jul 1, 05:40 UTCJul 2, 03:45 UTC22h 5m
2026-06-30 CYZ237 - Jun 30, 03:00 UTCJun 30, 09:40 UTC6h 40m
2026-06-27 CYZ278 - Jun 27, 11:00 UTCJun 27, 19:49 UTC8h 50m
2026-06-27 CYZ257 - Jun 27, 00:44 UTCJun 27, 07:10 UTC6h 25m
2026-06-25 CYZ258 - Jun 25, 11:04 UTCJun 25, 17:30 UTC6h 25m
2026-06-24 CYZ257 - Jun 24, 11:50 UTCJun 25, 06:50 UTC19h 0m
2026-06-24 CYZ257 - Jun 24, 11:39 UTCJun 25, 06:50 UTC19h 10m
2026-06-24 CYZ257 - Jun 24, 07:50 UTCJun 25, 06:50 UTC23h 0m
2026-06-24 CYZ294 - Jun 24, 06:04 UTCJun 25, 05:44 UTC23h 40m
2026-06-23 CYZ237 - Jun 23, 03:15 UTCJun 23, 09:34 UTC6h 20m
2026-06-20 CYZ278 - Jun 20, 10:49 UTCJun 20, 16:59 UTC6h 10m
2026-06-20 CYZ257 - Jun 20, 00:49 UTCJun 20, 07:19 UTC6h 30m
2026-06-18 CYZ258 - Jun 18, 10:55 UTCJun 18, 17:15 UTC6h 20m
2026-06-17 CYZ257 - Jun 17, 13:25 UTCJun 18, 07:10 UTC17h 45m
2026-06-17 CYZ257 - Jun 17, 09:50 UTCJun 18, 07:10 UTC21h 20m
2026-06-17 CYZ294 - Jun 17, 07:40 UTCJun 18, 04:10 UTC20h 30m
2026-06-16 CYZ237 - Jun 16, 03:25 UTCJun 16, 09:34 UTC6h 10m
2026-06-13 CYZ278 - Jun 13, 12:50 UTCJun 13, 19:25 UTC6h 35m
2026-06-13 CYZ257 - Jun 13, 01:20 UTCJun 13, 07:45 UTC6h 24m
2026-06-11 CYZ258 - Jun 11, 11:00 UTCJun 11, 17:25 UTC6h 25m
2026-06-11 CYZ257 - Jun 11, 00:45 UTCJun 11, 07:20 UTC6h 35m
2026-06-10 CYZ257 - Jun 10, 10:50 UTCJun 11, 07:20 UTC20h 30m
2026-06-10 CYZ257 - Jun 10, 08:30 UTCJun 11, 07:20 UTC22h 50m
2026-06-10 CYZ294 - Jun 10, 05:50 UTCJun 11, 05:45 UTC23h 55m
2026-06-10 CYZ294 - Jun 10, 05:30 UTCJun 11, 03:45 UTC22h 15m
2026-06-09 CYZ237 - Jun 9, 03:45 UTCJun 9, 10:20 UTC6h 35m
2026-06-06 CYZ278 - Jun 6, 12:00 UTCJun 6, 18:19 UTC6h 20m
2026-06-06 CYZ257 - Jun 6, 00:55 UTCJun 6, 07:20 UTC6h 25m
2026-06-04 CYZ258 - Jun 4, 12:20 UTCJun 4, 18:30 UTC6h 10m
2026-06-03 CYZ257 - Jun 3, 11:50 UTCJun 4, 07:25 UTC19h 35m
2026-06-03 CYZ257 - Jun 3, 11:20 UTCJun 4, 07:25 UTC20h 5m
2026-06-03 CYZ257 - Jun 3, 07:50 UTCJun 4, 07:25 UTC23h 35m
2026-06-03 CYZ294 - Jun 3, 05:50 UTCJun 4, 04:15 UTC22h 25m
2026-06-02 CYZ237 - Jun 2, 03:15 UTCJun 2, 09:45 UTC6h 30m

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

Mode-S 781DC7 frequently asked

What is Mode-S code 781DC7?
781DC7 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-221Y.
Where is Mode-S 781DC7 registered?
Mode-S code 781DC7 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 781DC7 broadcasting right now?
No active broadcast right now. Last signal was 5h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 781DC7, octal 36016707, decimal 7,871,943.
What flights does 781DC7 operate?
Mode-S 781DC7 has broadcast 7 distinct callsigns, including CYZ257, CYZ258, CYZ256, CYZ255, CYZ294.