sensors Mode-S transponder

7821A0

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-226X · BOEING 767-300

Hex
7821A0
Octal
36020640
Decimal
7,872,928
Country
CN
Tail
B-226X
Type
B763
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
3
Country
CN
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 7821A0.

Country allocation

The ICAO 24-bit address 7821A0 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
CSS127 - 3 2026-04-13
CSS128 - 2 2026-04-13
CSS170 - 1 2026-04-12

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 CSS128 - Apr 13, 21:30 UTCApr 13, 22:15 UTC45m
2026-04-13 CSS128 - Apr 13, 16:15 UTCApr 13, 18:30 UTC2h 15m
2026-04-13 CSS127 - Apr 13, 12:20 UTCApr 13, 13:05 UTC45m
2026-04-13 CSS127 - Apr 13, 12:00 UTCApr 13, 13:05 UTC1h 5m
2026-04-13 CSS127 - Apr 13, 09:30 UTCApr 13, 12:15 UTC2h 45m
2026-04-12 CSS170 - Apr 12, 17:15 UTCApr 12, 17:50 UTC35m

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-226X page for operator, model, and routing details .

Mode-S 7821A0 frequently asked

What is Mode-S code 7821A0?
7821A0 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-226X.
Where is Mode-S 7821A0 registered?
Mode-S code 7821A0 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7821A0 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 7821A0, octal 36020640, decimal 7,872,928.
What flights does 7821A0 operate?
Mode-S 7821A0 has broadcast 3 distinct callsigns, including CSS127, CSS128, CSS170.