sensors Mode-S transponder

781581

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-304D · AIRBUS A-350-900

Hex
781581
Octal
36012601
Decimal
7,869,825
Country
CN
Tail
B-304D
Type
A359
Photo of B-304D
Broadcasting now · callsign CES249 · 39,000 ft
Flights observed
9
Distinct callsigns
3
Country
CN
Last broadcast
1d ago

Current position

781581 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 781581 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 3 distinct

Callsign Airline Flights Last seen
CES250 China Eastern Airlines 5 2026-04-13
CES249 China Eastern Airlines 3 2026-04-13
CES524 China Eastern Airlines 1 2026-04-14

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-14 CES524 NRT → PVG Apr 14, 05:20 UTCApr 14, 06:50 UTC1h 30m
2026-04-13 CES250 BCN → PVG Apr 13, 16:15 UTCApr 13, 16:45 UTC30m
2026-04-13 CES250 BCN → PVG Apr 13, 16:00 UTCApr 13, 16:45 UTC45m
2026-04-13 CES250 BCN → PVG Apr 13, 12:20 UTCApr 13, 16:15 UTC3h 55m
2026-04-13 CES250 BCN → PVG Apr 13, 11:55 UTCApr 13, 14:15 UTC2h 20m
2026-04-13 CES250 BCN → PVG Apr 13, 09:35 UTCApr 13, 12:15 UTC2h 40m
2026-04-13 CES249 PVG → BCN Apr 13, 04:20 UTCApr 13, 05:35 UTC1h 15m
2026-04-13 CES249 PVG → BCN Apr 13, 03:55 UTCApr 13, 05:35 UTC1h 40m
2026-04-13 CES249 PVG → BCN Apr 13, 00:45 UTCApr 13, 04:15 UTC3h 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-304D page for operator, model, and routing details .

Mode-S 781581 frequently asked

What is Mode-S code 781581?
781581 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-304D.
Where is Mode-S 781581 registered?
Mode-S code 781581 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 781581 broadcasting right now?
Yes. Mode-S 781581 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 781581, octal 36012601, decimal 7,869,825.
What flights does 781581 operate?
Mode-S 781581 has broadcast 3 distinct callsigns, including CES250, CES249, CES524.