Apparatus

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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 5h ago
Flights observed
368
Distinct callsigns
20
Country
TW
Last broadcast
5h 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 40 2026-06-23
CAL221 - 33 2026-06-22
CAL222 - 32 2026-06-22
CAL220 - 26 2026-06-22
CAL201 - 16 2026-06-23
CAL173 - 14 2026-07-02
CAL105 - 14 2026-07-06
CAL202 - 13 2026-06-23
CAL704 - 12 2026-07-03
CAL703 - 12 2026-07-03
CAL104 - 12 2026-07-06
CAL111 - 11 2026-06-30
CAL172 - 10 2026-07-02
CAL919 - 8 2026-06-29
CAL701 China Airlines 8 2026-07-03
CAL153 China Airlines 8 2026-05-13
CAL110 China Airlines 8 2026-06-29
CAL702 - 7 2026-07-04
CAL131 - 7 2026-07-13
CAL130 - 7 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 CAL551 - Jul 14, 01:05 UTCJul 14, 01:50 UTC45m
2026-07-13 CAL131 - Jul 13, 06:30 UTCJul 13, 10:00 UTC3h 30m
2026-07-13 CAL130 - Jul 13, 01:05 UTCJul 13, 04:45 UTC3h 40m
2026-07-12 CAL732 - Jul 12, 02:15 UTCJul 12, 12:20 UTC10h 5m
2026-07-10 CAL101 - Jul 10, 08:40 UTCJul 10, 09:00 UTC20m
2026-07-10 CAL101 - Jul 10, 06:00 UTCJul 10, 07:10 UTC1h 10m
2026-07-10 CAL100 - Jul 10, 01:05 UTCJul 10, 04:00 UTC2h 55m
2026-07-09 CAL131 - Jul 9, 09:55 UTCJul 9, 10:25 UTC30m
2026-07-09 CAL131 - Jul 9, 06:35 UTCJul 9, 08:30 UTC1h 55m
2026-07-09 CAL130 - Jul 9, 02:50 UTCJul 9, 04:40 UTC1h 50m
2026-07-09 CAL130 - Jul 9, 01:15 UTCJul 9, 01:25 UTC10m
2026-07-08 CAL131 - Jul 8, 09:40 UTCJul 8, 10:00 UTC20m
2026-07-08 CAL131 - Jul 8, 06:35 UTCJul 8, 08:30 UTC1h 55m
2026-07-08 CAL130 - Jul 8, 02:35 UTCJul 8, 04:35 UTC2h 0m
2026-07-08 CAL130 - Jul 8, 01:00 UTCJul 8, 01:20 UTC20m
2026-07-07 CAL924 HKG → TPE Jul 7, 13:35 UTCJul 7, 15:00 UTC1h 25m
2026-07-07 CAL923 - Jul 7, 11:40 UTCJul 7, 11:50 UTC10m
2026-07-07 CAL923 - Jul 7, 10:35 UTCJul 7, 11:05 UTC30m
2026-07-07 CAL552 TPE → TPE Jul 7, 01:10 UTCJul 7, 09:20 UTC8h 10m
2026-07-06 CAL105 - Jul 6, 12:05 UTCJul 6, 12:25 UTC20m
2026-07-06 CAL105 - Jul 6, 09:35 UTCJul 6, 10:55 UTC1h 20m
2026-07-06 CAL104 - Jul 6, 06:15 UTCJul 6, 07:35 UTC1h 20m
2026-07-06 CAL104 - Jul 6, 04:40 UTCJul 6, 04:50 UTC10m
2026-07-05 CAL832 - Jul 5, 06:40 UTCJul 5, 10:15 UTC3h 35m
2026-07-05 CAL831 TPE → BKK Jul 5, 01:45 UTCJul 5, 04:55 UTC3h 10m
2026-07-04 CAL522 - Jul 4, 10:30 UTCJul 4, 11:55 UTC1h 25m
2026-07-04 CAL521 - Jul 4, 06:30 UTCJul 4, 06:45 UTC15m
2026-07-04 CAL702 - Jul 4, 03:00 UTCJul 4, 04:45 UTC1h 45m
2026-07-03 CAL701 TPE → MNL Jul 3, 23:55 UTCJul 4, 01:45 UTC1h 50m
2026-07-03 CAL704 - Jul 3, 10:05 UTCJul 3, 11:50 UTC1h 45m
2026-07-03 CAL703 - Jul 3, 06:45 UTCJul 3, 08:30 UTC1h 45m
2026-07-03 CAL702 - Jul 3, 03:30 UTCJul 3, 05:10 UTC1h 40m
2026-07-02 CAL701 TPE → MNL Jul 2, 23:55 UTCJul 3, 01:45 UTC1h 50m
2026-07-02 CAL173 KIX → TPE Jul 2, 10:40 UTCJul 2, 13:00 UTC2h 20m
2026-07-02 CAL172 TPE → KIX Jul 2, 06:51 UTCJul 2, 09:05 UTC2h 14m
2026-07-01 MDA991 - Jul 1, 01:10 UTCJul 1, 05:35 UTC4h 25m
2026-06-30 CAL704 - Jun 30, 09:35 UTCJun 30, 11:10 UTC1h 35m
2026-06-30 CAL703 - Jun 30, 06:15 UTCJun 30, 08:00 UTC1h 45m
2026-06-30 CAL111 - Jun 30, 04:10 UTCJun 30, 04:35 UTC25m
2026-06-29 CAL110 TPE → FUK Jun 29, 23:05 UTCJun 29, 23:19 UTC15m
2026-06-29 CAL920 - Jun 29, 12:39 UTCJun 29, 14:09 UTC1h 30m
2026-06-29 CAL919 - Jun 29, 10:34 UTCJun 29, 10:50 UTC15m
2026-06-29 CAL919 - Jun 29, 09:20 UTCJun 29, 09:44 UTC25m
2026-06-29 CAL834 - Jun 29, 04:14 UTCJun 29, 07:34 UTC3h 20m
2026-06-28 CAL833 TPE → BKK Jun 28, 23:20 UTCJun 29, 02:25 UTC3h 5m
2026-06-28 CAL920 - Jun 28, 13:00 UTCJun 28, 14:19 UTC1h 20m
2026-06-28 CAL919 - Jun 28, 10:30 UTCJun 28, 10:44 UTC15m
2026-06-28 CAL919 - Jun 28, 09:25 UTCJun 28, 09:50 UTC25m
2026-06-28 CAL834 - Jun 28, 04:10 UTCJun 28, 07:34 UTC3h 25m
2026-06-27 CAL833 TPE → BKK Jun 27, 23:19 UTCJun 28, 02:25 UTC3h 5m

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 5h 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, CAL201.