Apparatus

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sensors Mode-S transponder

8991A8

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18360 · AIRBUS A-330-300

Hex
8991A8
Octal
42310650
Decimal
9,015,720
Country
TW
Tail
B-18360
Type
A333
No current signal · last broadcast 2h ago
Flights observed
188
Distinct callsigns
12
Country
TW
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 8991A8.

Country allocation

The ICAO 24-bit address 8991A8 falls within the block assigned to Taiwan (TW) by ICAO Annex 10, Volume III. Every aircraft registered in Taiwan 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 12 distinct

Callsign Airline Flights Last seen
CAL221 China Airlines 45 2026-05-29
CAL223 China Airlines 44 2026-05-29
CAL220 China Airlines 34 2026-05-29
CAL222 China Airlines 30 2026-05-29
CAL201 China Airlines 15 2026-05-28
CAL202 China Airlines 13 2026-05-28
CAL111 - 2 2026-04-13
CAL7847 - 1 2026-04-14
CAL704 - 1 2026-04-13
CAL703 - 1 2026-04-13
CAL157 - 1 2026-04-14
75 - 1 2026-04-25

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 CAL223 HND → TSA May 29, 23:15 UTCMay 30, 00:30 UTC1h 15m
2026-05-29 CAL222 TSA → HND May 29, 10:20 UTCMay 29, 13:00 UTC2h 40m
2026-05-29 CAL221 HND → TSA May 29, 08:25 UTCMay 29, 08:50 UTC25m
2026-05-29 CAL221 HND → TSA May 29, 05:45 UTCMay 29, 07:00 UTC1h 15m
2026-05-29 CAL220 TSA → HND May 29, 02:40 UTCMay 29, 03:40 UTC1h 0m
2026-05-29 CAL220 TSA → HND May 29, 01:10 UTCMay 29, 01:25 UTC15m
2026-05-28 CAL202 SHA → TSA May 28, 09:35 UTCMay 28, 10:00 UTC25m
2026-05-28 CAL201 TSA → SHA May 28, 04:35 UTCMay 28, 05:00 UTC25m
2026-05-28 CAL223 HND → TSA May 28, 01:30 UTCMay 28, 01:55 UTC25m
2026-05-27 CAL223 HND → TSA May 27, 23:05 UTCMay 28, 00:10 UTC1h 5m
2026-05-27 CAL222 TSA → HND May 27, 10:15 UTCMay 27, 13:10 UTC2h 55m
2026-05-27 CAL221 HND → TSA May 27, 08:25 UTCMay 27, 08:40 UTC15m
2026-05-27 CAL221 HND → TSA May 27, 05:55 UTCMay 27, 07:00 UTC1h 6m
2026-05-27 CAL220 TSA → HND May 27, 01:05 UTCMay 27, 03:54 UTC2h 50m
2026-05-26 CAL202 SHA → TSA May 26, 09:35 UTCMay 26, 10:10 UTC35m
2026-05-26 CAL201 TSA → SHA May 26, 04:24 UTCMay 26, 04:54 UTC30m
2026-05-26 CAL223 HND → TSA May 26, 01:49 UTCMay 26, 02:24 UTC35m
2026-05-25 CAL223 HND → TSA May 25, 23:14 UTCMay 26, 00:24 UTC1h 10m
2026-05-25 CAL222 TSA → HND May 25, 10:15 UTCMay 25, 13:05 UTC2h 50m
2026-05-25 CAL221 HND → TSA May 25, 08:25 UTCMay 25, 08:50 UTC25m
2026-05-25 CAL221 HND → TSA May 25, 06:00 UTCMay 25, 07:05 UTC1h 5m
2026-05-25 CAL220 TSA → HND May 25, 02:50 UTCMay 25, 04:05 UTC1h 15m
2026-05-24 CAL202 SHA → TSA May 24, 05:05 UTCMay 24, 11:05 UTC6h 0m
2026-05-24 CAL223 HND → TSA May 24, 01:45 UTCMay 24, 02:25 UTC40m
2026-05-23 CAL223 HND → TSA May 23, 23:15 UTCMay 24, 00:25 UTC1h 10m
2026-05-23 CAL222 TSA → HND May 23, 10:30 UTCMay 23, 13:30 UTC3h 0m
2026-05-23 CAL221 HND → TSA May 23, 08:45 UTCMay 23, 09:00 UTC15m
2026-05-23 CAL221 HND → TSA May 23, 06:05 UTCMay 23, 07:15 UTC1h 10m
2026-05-23 CAL220 TSA → HND May 23, 01:10 UTCMay 23, 03:50 UTC2h 39m
2026-05-22 CAL223 HND → TSA May 22, 02:00 UTCMay 22, 02:30 UTC30m
2026-05-21 CAL223 HND → TSA May 21, 23:15 UTCMay 22, 00:25 UTC1h 10m
2026-05-21 CAL222 TSA → HND May 21, 10:20 UTCMay 21, 13:10 UTC2h 50m
2026-05-21 CAL221 HND → TSA May 21, 08:50 UTCMay 21, 09:00 UTC10m
2026-05-21 CAL221 HND → TSA May 21, 05:55 UTCMay 21, 07:05 UTC1h 10m
2026-05-21 CAL220 TSA → HND May 21, 02:35 UTCMay 21, 03:45 UTC1h 10m
2026-05-21 CAL220 TSA → HND May 21, 01:05 UTCMay 21, 01:25 UTC20m
2026-05-20 CAL202 SHA → TSA May 20, 09:45 UTCMay 20, 10:15 UTC30m
2026-05-20 CAL201 TSA → SHA May 20, 04:40 UTCMay 20, 05:05 UTC25m
2026-05-20 CAL223 HND → TSA May 20, 01:40 UTCMay 20, 02:20 UTC40m
2026-05-19 CAL223 HND → TSA May 19, 23:00 UTCMay 20, 00:10 UTC1h 10m
2026-05-19 CAL222 TSA → HND May 19, 10:10 UTCMay 19, 13:05 UTC2h 55m
2026-05-19 CAL221 HND → TSA May 19, 08:10 UTCMay 19, 08:25 UTC15m
2026-05-19 CAL221 HND → TSA May 19, 05:45 UTCMay 19, 06:45 UTC1h 0m
2026-05-19 CAL220 TSA → HND May 19, 01:05 UTCMay 19, 04:00 UTC2h 55m
2026-05-18 CAL201 TSA → SHA May 18, 04:30 UTCMay 18, 09:55 UTC5h 25m
2026-05-18 CAL223 HND → TSA May 18, 01:40 UTCMay 18, 02:25 UTC45m
2026-05-17 CAL223 HND → TSA May 17, 23:15 UTCMay 18, 00:15 UTC1h 0m
2026-05-17 CAL222 TSA → HND May 17, 10:10 UTCMay 17, 13:10 UTC3h 0m
2026-05-17 CAL221 HND → TSA May 17, 08:20 UTCMay 17, 08:40 UTC20m
2026-05-17 CAL221 HND → TSA May 17, 05:55 UTCMay 17, 07:45 UTC1h 50m

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-18360 page for operator, model, and routing details .

Mode-S 8991A8 frequently asked

What is Mode-S code 8991A8?
8991A8 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18360.
Where is Mode-S 8991A8 registered?
Mode-S code 8991A8 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991A8 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991A8, octal 42310650, decimal 9,015,720.
What flights does 8991A8 operate?
Mode-S 8991A8 has broadcast 12 distinct callsigns, including CAL221, CAL223, CAL220, CAL222, CAL201.