sensors Mode-S transponder

781521

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-302W · AIRBUS A-320neo

Hex
781521
Octal
36012441
Decimal
7,869,729
Country
CN
Tail
B-302W
Type
A20N
No current signal · last broadcast Apr 16, 07:49 UTC
Flights observed
4
Distinct callsigns
4
Country
CN
Last broadcast
Apr 16, 07:49 UTC

Last known position

Most recent position reported by Mode-S 781521.

Country allocation

The ICAO 24-bit address 781521 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 4 distinct

Callsign Airline Flights Last seen
CES6328 China Eastern Airlines 1 2026-04-14
CES6302 China Eastern Airlines 1 2026-04-14
CES2332 China Eastern Airlines 1 2026-04-16
CES2331 China Eastern Airlines 1 2026-04-16

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-16 CES2332 PVG → TYN Apr 16, 07:29 UTCApr 16, 07:49 UTC20m
2026-04-16 CES2331 TYN → PVG Apr 16, 05:49 UTCApr 16, 06:05 UTC15m
2026-04-14 CES6302 CAN → PKX Apr 14, 23:50 UTCApr 15, 00:00 UTC10m
2026-04-14 CES6328 ZHA → PVG Apr 14, 05:15 UTCApr 14, 05:35 UTC20m

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-302W page for operator, model, and routing details .

Mode-S 781521 frequently asked

What is Mode-S code 781521?
781521 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-302W.
Where is Mode-S 781521 registered?
Mode-S code 781521 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 781521 broadcasting right now?
No active broadcast right now. Last signal was Apr 16, 07:49 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 781521, octal 36012441, decimal 7,869,729.
What flights does 781521 operate?
Mode-S 781521 has broadcast 4 distinct callsigns, including CES6328, CES6302, CES2332, CES2331.