sensors Mode-S transponder

8991AA

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18358 · AIRBUS A-330-300

Hex
8991AA
Octal
42310652
Decimal
9,015,722
Country
TW
Tail
B-18358
Type
A333
No current signal · last broadcast 31m ago
Flights observed
195
Distinct callsigns
20
Country
TW
Last broadcast
31m ago

Last known position

Most recent position reported by Mode-S 8991AA.

Country allocation

The ICAO 24-bit address 8991AA 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 20 distinct

Callsign Airline Flights Last seen
CAL223 China Airlines 18 2026-04-29
CAL221 China Airlines 16 2026-04-28
CAL222 China Airlines 12 2026-04-28
CAL220 China Airlines 12 2026-04-28
CAL704 China Airlines 9 2026-05-29
CAL703 China Airlines 9 2026-05-29
CAL202 China Airlines 8 2026-04-29
CAL201 China Airlines 8 2026-04-29
CAL153 China Airlines 8 2026-05-13
CAL105 China Airlines 8 2026-05-14
CAL173 China Airlines 7 2026-05-27
CAL111 China Airlines 7 2026-05-29
CAL110 China Airlines 6 2026-05-28
CAL104 China Airlines 6 2026-05-14
CAL172 China Airlines 5 2026-05-27
CAL919 China Airlines 4 2026-05-04
CAL702 China Airlines 4 2026-05-27
CAL701 China Airlines 4 2026-05-26
CAL163 China Airlines 4 2026-05-26
CAL152 China Airlines 4 2026-05-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 CAL833 TPE → BKK May 29, 23:30 UTCMay 30, 02:30 UTC3h 0m
2026-05-29 CAL704 MNL → TPE May 29, 09:45 UTCMay 29, 11:20 UTC1h 35m
2026-05-29 CAL703 TPE → MNL May 29, 06:00 UTCMay 29, 07:40 UTC1h 40m
2026-05-29 CAL111 FUK → TPE May 29, 04:05 UTCMay 29, 04:30 UTC25m
2026-05-28 CAL110 TPE → FUK May 28, 23:10 UTCMay 28, 23:30 UTC20m
2026-05-28 CAL704 MNL → TPE May 28, 09:20 UTCMay 28, 11:05 UTC1h 45m
2026-05-28 CAL703 TPE → MNL May 28, 05:55 UTCMay 28, 07:45 UTC1h 50m
2026-05-28 CAL111 FUK → TPE May 28, 04:10 UTCMay 28, 04:30 UTC20m
2026-05-27 CAL110 TPE → FUK May 27, 23:10 UTCMay 27, 23:35 UTC25m
2026-05-27 CAL173 KIX → TPE May 27, 12:20 UTCMay 27, 12:45 UTC25m
2026-05-27 CAL173 KIX → TPE May 27, 10:20 UTCMay 27, 10:50 UTC30m
2026-05-27 CAL172 TPE → KIX May 27, 06:29 UTCMay 27, 08:45 UTC2h 16m
2026-05-27 CAL702 MNL → TPE May 27, 02:49 UTCMay 27, 04:39 UTC1h 50m
2026-05-26 CAL701 TPE → MNL May 26, 23:29 UTCMay 27, 01:19 UTC1h 50m
2026-05-26 CAL163 ICN → TPE May 26, 13:10 UTCMay 26, 13:40 UTC30m
2026-05-26 CAL163 ICN → TPE May 26, 11:34 UTCMay 26, 12:00 UTC25m
2026-05-26 CAL162 TPE → ICN May 26, 09:29 UTCMay 26, 09:55 UTC25m
2026-05-26 CAL162 TPE → ICN May 26, 07:55 UTCMay 26, 08:10 UTC15m
2026-05-26 CAL161 ICN → TPE May 26, 04:10 UTCMay 26, 06:10 UTC2h 0m
2026-05-26 CAL160 TPE → ICN May 26, 00:04 UTCMay 26, 02:10 UTC2h 5m
2026-05-25 CAL704 MNL → TPE May 25, 09:40 UTCMay 25, 11:25 UTC1h 45m
2026-05-25 CAL703 TPE → MNL May 25, 05:55 UTCMay 25, 07:50 UTC1h 55m
2026-05-25 CAL111 FUK → TPE May 25, 04:10 UTCMay 25, 04:35 UTC25m
2026-05-24 CAL110 TPE → FUK May 24, 23:10 UTCMay 24, 23:30 UTC20m
2026-05-24 CAL704 MNL → TPE May 24, 09:30 UTCMay 24, 11:15 UTC1h 45m
2026-05-24 CAL703 TPE → MNL May 24, 05:55 UTCMay 24, 07:45 UTC1h 50m
2026-05-24 CAL121 OKA → TPE May 24, 04:00 UTCMay 24, 04:30 UTC30m
2026-05-24 CAL120 TPE → OKA May 24, 00:15 UTCMay 24, 00:30 UTC15m
2026-05-23 CAL704 MNL → TPE May 23, 09:45 UTCMay 23, 11:25 UTC1h 40m
2026-05-23 CAL703 TPE → MNL May 23, 06:25 UTCMay 23, 08:10 UTC1h 45m
2026-05-23 CAL702 MNL → TPE May 23, 03:05 UTCMay 23, 04:55 UTC1h 50m
2026-05-22 CAL701 TPE → MNL May 22, 23:40 UTCMay 23, 01:40 UTC2h 0m
2026-05-22 CAL704 MNL → TPE May 22, 09:05 UTCMay 22, 10:55 UTC1h 50m
2026-05-22 CAL703 TPE → MNL May 22, 05:55 UTCMay 22, 07:45 UTC1h 50m
2026-05-21 CAL834 BKK → TPE May 21, 04:10 UTCMay 21, 07:35 UTC3h 25m
2026-05-20 CAL833 TPE → BKK May 20, 23:40 UTCMay 21, 02:45 UTC3h 5m
2026-05-20 CAL704 MNL → TPE May 20, 09:05 UTCMay 20, 10:50 UTC1h 45m
2026-05-20 CAL703 TPE → MNL May 20, 05:45 UTCMay 20, 07:35 UTC1h 50m
2026-05-20 CAL111 FUK → TPE May 20, 04:00 UTCMay 20, 04:20 UTC20m
2026-05-20 CAL111 FUK → TPE May 20, 02:25 UTCMay 20, 02:35 UTC10m
2026-05-19 CAL110 TPE → FUK May 19, 23:10 UTCMay 19, 23:30 UTC20m
2026-05-19 CAL704 MNL → TPE May 19, 09:15 UTCMay 19, 11:00 UTC1h 45m
2026-05-19 CAL703 TPE → MNL May 19, 05:45 UTCMay 19, 07:30 UTC1h 45m
2026-05-19 CAL121 OKA → TPE May 19, 03:50 UTCMay 19, 04:20 UTC30m
2026-05-19 CAL120 TPE → OKA May 19, 00:30 UTCMay 19, 00:50 UTC20m
2026-05-18 CAL704 MNL → TPE May 18, 09:10 UTCMay 18, 10:50 UTC1h 40m
2026-05-18 CAL703 TPE → MNL May 18, 05:55 UTCMay 18, 07:40 UTC1h 45m
2026-05-18 CAL111 FUK → TPE May 18, 04:00 UTCMay 18, 04:25 UTC25m
2026-05-17 CAL110 TPE → FUK May 17, 23:05 UTCMay 17, 23:20 UTC15m
2026-05-17 CAL832 BKK → TPE May 17, 06:40 UTCMay 17, 09:55 UTC3h 15m

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-18358 page for operator, model, and routing details .

Mode-S 8991AA frequently asked

What is Mode-S code 8991AA?
8991AA is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18358.
Where is Mode-S 8991AA registered?
Mode-S code 8991AA is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991AA broadcasting right now?
No active broadcast right now. Last signal was 31m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991AA, octal 42310652, decimal 9,015,722.
What flights does 8991AA operate?
Mode-S 8991AA has broadcast 20 distinct callsigns, including CAL223, CAL221, CAL222, CAL220, CAL704.