sensors Mode-S transponder

7821A9

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-226Q · BOEING 787-9 Dreamliner

Hex
7821A9
Octal
36020651
Decimal
7,872,937
Country
CN
Tail
B-226Q
Type
B789
No current signal · last broadcast 12h ago
Flights observed
7
Distinct callsigns
3
Country
CN
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 7821A9.

Country allocation

The ICAO 24-bit address 7821A9 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
CES213 China Eastern Airlines 4 2026-04-13
CES214 - 2 2026-04-13
CES545 China Eastern Airlines 1 2026-04-14

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 CES545 PVG → SIN Apr 14, 09:30 UTCApr 14, 10:40 UTC1h 10m
2026-04-13 CES214 - Apr 13, 19:50 UTCApr 13, 23:30 UTC3h 40m
2026-04-13 CES214 - Apr 13, 17:15 UTCApr 13, 19:50 UTC2h 35m
2026-04-13 CES213 PVG → LGW Apr 13, 12:20 UTCApr 13, 13:45 UTC1h 25m
2026-04-13 CES213 PVG → LGW Apr 13, 11:55 UTCApr 13, 13:45 UTC1h 50m
2026-04-13 CES213 PVG → LGW Apr 13, 09:40 UTCApr 13, 12:15 UTC2h 35m
2026-04-13 CES213 PVG → LGW Apr 13, 05:25 UTCApr 13, 07:25 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-226Q page for operator, model, and routing details .

Mode-S 7821A9 frequently asked

What is Mode-S code 7821A9?
7821A9 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-226Q.
Where is Mode-S 7821A9 registered?
Mode-S code 7821A9 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7821A9 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 7821A9, octal 36020651, decimal 7,872,937.
What flights does 7821A9 operate?
Mode-S 7821A9 has broadcast 3 distinct callsigns, including CES213, CES214, CES545.