Apparatus

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sensors Mode-S transponder

8991BC

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18315 · AIRBUS A-330-300

Hex
8991BC
Octal
42310674
Decimal
9,015,740
Country
TW
Tail
B-18315
Type
A333
No current signal · last broadcast 45m ago
Flights observed
370
Distinct callsigns
20
Country
TW
Last broadcast
45m ago

Last known position

Most recent position reported by Mode-S 8991BC.

Country allocation

The ICAO 24-bit address 8991BC 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
CAL919 - 22 2026-06-24
CAL833 - 17 2026-07-14
CAL111 - 17 2026-07-07
CAL173 - 16 2026-07-13
CAL110 China Airlines 16 2026-07-07
CAL920 - 15 2026-06-24
CAL834 China Airlines 15 2026-06-11
CAL163 - 14 2026-07-06
CAL162 - 12 2026-07-06
CAL161 - 12 2026-07-06
CAL117 - 11 2026-06-17
CAL109 - 11 2026-06-28
CAL521 - 10 2026-06-26
CAL172 - 10 2026-07-13
CAL160 - 10 2026-07-06
CAL105 - 10 2026-07-01
CAL702 - 9 2026-07-12
CAL701 - 9 2026-07-11
CAL522 - 9 2026-06-26
CAL153 - 9 2026-07-10

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 CAL833 - Jul 14, 02:30 UTCJul 14, 02:55 UTC25m
2026-07-13 CAL833 - Jul 13, 23:30 UTCJul 14, 00:30 UTC1h 0m
2026-07-13 CAL173 KIX → TPE Jul 13, 10:35 UTCJul 13, 12:55 UTC2h 20m
2026-07-13 CAL172 TPE → KIX Jul 13, 06:45 UTCJul 13, 09:10 UTC2h 25m
2026-07-12 CAL173 - Jul 12, 11:20 UTCJul 12, 13:45 UTC2h 25m
2026-07-12 CAL172 TPE → KIX Jul 12, 06:30 UTCJul 12, 08:50 UTC2h 20m
2026-07-12 CAL702 MNL → TPE Jul 12, 03:10 UTCJul 12, 04:50 UTC1h 40m
2026-07-11 CAL701 - Jul 11, 23:35 UTCJul 12, 01:30 UTC1h 55m
2026-07-10 CAL153 - Jul 10, 07:25 UTCJul 10, 07:50 UTC25m
2026-07-10 CAL153 - Jul 10, 05:30 UTCJul 10, 06:15 UTC45m
2026-07-10 CAL152 - Jul 10, 01:25 UTCJul 10, 03:50 UTC2h 25m
2026-07-09 - TPE → TPE Jul 9, 17:25 UTCJul 9, 17:40 UTC15m
2026-07-09 CAL173 - Jul 9, 12:15 UTCJul 9, 13:00 UTC45m
2026-07-09 CAL173 - Jul 9, 10:20 UTCJul 9, 11:00 UTC40m
2026-07-09 CAL172 - Jul 9, 08:05 UTCJul 9, 08:50 UTC45m
2026-07-09 CAL172 - Jul 9, 06:35 UTCJul 9, 06:50 UTC15m
2026-07-08 CAL153 KIX → TPE Jul 8, 05:20 UTCJul 8, 07:50 UTC2h 30m
2026-07-08 CAL152 TPE → KIX Jul 8, 01:35 UTCJul 8, 03:55 UTC2h 20m
2026-07-07 CAL704 - Jul 7, 09:55 UTCJul 7, 11:45 UTC1h 50m
2026-07-07 CAL703 - Jul 7, 06:05 UTCJul 7, 07:55 UTC1h 50m
2026-07-07 CAL111 - Jul 7, 04:10 UTCJul 7, 04:30 UTC20m
2026-07-07 CAL111 - Jul 7, 02:45 UTCJul 7, 02:55 UTC10m
2026-07-07 CAL110 TPE → FUK Jul 7, 00:20 UTCJul 7, 00:35 UTC15m
2026-07-06 CAL110 TPE → FUK Jul 6, 23:00 UTCJul 6, 23:25 UTC25m
2026-07-06 CAL163 - Jul 6, 13:40 UTCJul 6, 14:00 UTC20m
2026-07-06 CAL163 - Jul 6, 12:05 UTCJul 6, 12:35 UTC30m
2026-07-06 CAL162 TPE → ICN Jul 6, 07:50 UTCJul 6, 10:00 UTC2h 10m
2026-07-06 CAL161 ICN → TPE Jul 6, 04:20 UTCJul 6, 06:25 UTC2h 5m
2026-07-06 CAL160 TPE → ICN Jul 6, 00:40 UTCJul 6, 02:45 UTC2h 5m
2026-07-05 CAL836 - Jul 5, 10:40 UTCJul 5, 14:25 UTC3h 45m
2026-07-05 CAL835 TPE → BKK Jul 5, 05:45 UTCJul 5, 08:55 UTC3h 10m
2026-07-04 CAL131 - Jul 4, 10:00 UTCJul 4, 10:20 UTC20m
2026-07-04 CAL131 - Jul 4, 06:45 UTCJul 4, 08:40 UTC1h 55m
2026-07-04 CAL130 - Jul 4, 03:15 UTCJul 4, 05:20 UTC2h 5m
2026-07-04 CAL130 - Jul 4, 01:55 UTCJul 4, 02:10 UTC15m
2026-07-03 CAL832 - Jul 3, 07:25 UTCJul 3, 10:50 UTC3h 25m
2026-07-03 CAL831 TPE → BKK Jul 3, 02:10 UTCJul 3, 05:35 UTC3h 25m
2026-07-02 CAL131 - Jul 2, 09:50 UTCJul 2, 10:10 UTC20m
2026-07-02 CAL131 - Jul 2, 06:20 UTCJul 2, 08:25 UTC2h 5m
2026-07-02 CAL130 - Jul 2, 01:05 UTCJul 2, 04:20 UTC3h 15m
2026-07-01 CAL105 - Jul 1, 12:15 UTCJul 1, 12:35 UTC20m
2026-07-01 CAL105 - Jul 1, 09:30 UTCJul 1, 10:50 UTC1h 20m
2026-07-01 CAL104 - Jul 1, 04:55 UTCJul 1, 07:50 UTC2h 55m
2026-06-30 CAL552 - Jun 30, 01:00 UTCJun 30, 08:55 UTC7h 55m
2026-06-29 CAL704 - Jun 29, 09:14 UTCJun 29, 10:55 UTC1h 40m
2026-06-29 CAL703 - Jun 29, 05:59 UTCJun 29, 07:40 UTC1h 40m
2026-06-29 CAL111 - Jun 29, 04:04 UTCJun 29, 04:25 UTC20m
2026-06-29 CAL110 TPE → FUK Jun 29, 00:20 UTCJun 29, 00:34 UTC15m
2026-06-28 CAL110 TPE → FUK Jun 28, 23:04 UTCJun 28, 23:25 UTC20m
2026-06-28 CAL109 - Jun 28, 14:34 UTCJun 28, 14:59 UTC25m

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-18315 page for operator, model, and routing details .

Mode-S 8991BC frequently asked

What is Mode-S code 8991BC?
8991BC is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18315.
Where is Mode-S 8991BC registered?
Mode-S code 8991BC is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991BC broadcasting right now?
No active broadcast right now. Last signal was 45m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991BC, octal 42310674, decimal 9,015,740.
What flights does 8991BC operate?
Mode-S 8991BC has broadcast 20 distinct callsigns, including CAL919, CAL833, CAL111, CAL173, CAL110.