Apparatus

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sensors Mode-S transponder

8991B6

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18308 · AIRBUS A-330-300

Hex
8991B6
Octal
42310666
Decimal
9,015,734
Country
TW
Tail
B-18308
Type
A333
No current signal · last broadcast 2h ago
Flights observed
250
Distinct callsigns
20
Country
TW
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 8991B6.

Country allocation

The ICAO 24-bit address 8991B6 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
CAL131 - 17 2026-07-05
CAL792 - 13 2026-07-09
CAL836 - 12 2026-07-03
CAL161 - 12 2026-07-14
CAL835 - 11 2026-07-10
CAL791 - 11 2026-07-09
CAL130 - 11 2026-07-05
CAL160 - 9 2026-07-14
CAL151 China Airlines 8 2026-05-01
MDA991 - 6 2026-06-04
CAL919 - 6 2026-06-26
CAL163 - 6 2026-07-13
CAL120 - 6 2026-07-03
CAL117 - 6 2026-07-09
MDA992 - 5 2026-07-12
CAL704 - 5 2026-07-04
CAL703 - 5 2026-07-04
CAL521 China Airlines 5 2026-05-28
CAL162 - 5 2026-07-13
CAL157 China Airlines 5 2026-06-08

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 CAL161 - Jul 14, 04:25 UTCJul 14, 05:00 UTC35m
2026-07-14 CAL160 TPE → ICN Jul 14, 00:15 UTCJul 14, 02:25 UTC2h 10m
2026-07-13 CAL163 ICN → TPE Jul 13, 11:55 UTCJul 13, 14:00 UTC2h 5m
2026-07-13 CAL162 TPE → ICN Jul 13, 08:10 UTCJul 13, 10:15 UTC2h 5m
2026-07-13 CAL161 - Jul 13, 04:10 UTCJul 13, 06:10 UTC2h 0m
2026-07-13 CAL160 TPE → ICN Jul 13, 00:10 UTCJul 13, 02:15 UTC2h 5m
2026-07-12 MDA992 TPE → TPE Jul 12, 02:45 UTCJul 12, 07:05 UTC4h 20m
2026-07-12 CAL836D - Jul 12, 00:01 UTCJul 12, 00:35 UTC35m
2026-07-11 CAL836D - Jul 11, 21:20 UTCJul 11, 21:40 UTC20m
2026-07-10 CAL835 - Jul 10, 06:05 UTCJul 10, 09:15 UTC3h 10m
2026-07-09 CAL117 - Jul 9, 13:55 UTCJul 9, 14:30 UTC35m
2026-07-09 CAL117 - Jul 9, 12:30 UTCJul 9, 13:00 UTC30m
2026-07-09 CAL116 - Jul 9, 10:35 UTCJul 9, 10:50 UTC15m
2026-07-09 CAL116 - Jul 9, 09:15 UTCJul 9, 09:40 UTC25m
2026-07-09 CAL792 - Jul 9, 06:15 UTCJul 9, 07:35 UTC1h 20m
2026-07-09 CAL791 - Jul 9, 01:10 UTCJul 9, 02:20 UTC1h 10m
2026-07-08 CAL105 NRT → TPE Jul 8, 09:20 UTCJul 8, 12:15 UTC2h 55m
2026-07-08 CAL104 TPE → NRT Jul 8, 04:30 UTCJul 8, 07:30 UTC3h 0m
2026-07-05 CAL131 - Jul 5, 09:45 UTCJul 5, 10:20 UTC35m
2026-07-05 CAL131 - Jul 5, 06:30 UTCJul 5, 08:25 UTC1h 55m
2026-07-05 CAL130 - Jul 5, 01:15 UTCJul 5, 04:35 UTC3h 20m
2026-07-04 CAL704 - Jul 4, 09:10 UTCJul 4, 10:50 UTC1h 40m
2026-07-04 CAL703 TPE → MNL Jul 4, 05:50 UTCJul 4, 07:35 UTC1h 45m
2026-07-04 CAL111 - Jul 4, 04:15 UTCJul 4, 04:30 UTC15m
2026-07-04 CAL111 - Jul 4, 02:40 UTCJul 4, 03:05 UTC25m
2026-07-04 CAL110 TPE → FUK Jul 4, 00:30 UTCJul 4, 00:45 UTC15m
2026-07-03 CAL110 TPE → FUK Jul 3, 23:10 UTCJul 3, 23:35 UTC25m
2026-07-03 CAL836 - Jul 3, 11:05 UTCJul 3, 14:30 UTC3h 25m
2026-07-03 CAL835 TPE → BKK Jul 3, 05:45 UTCJul 3, 09:05 UTC3h 20m
2026-07-03 CAL121 - Jul 3, 03:45 UTCJul 3, 04:10 UTC25m
2026-07-03 CAL120 - Jul 3, 01:15 UTCJul 3, 01:30 UTC15m
2026-07-03 CAL120 - Jul 3, 00:20 UTCJul 3, 00:45 UTC25m
2026-07-02 CAL187 PUS → TPE Jul 2, 11:20 UTCJul 2, 13:15 UTC1h 55m
2026-07-02 CAL186 TPE → PUS Jul 2, 08:10 UTCJul 2, 09:55 UTC1h 45m
2026-07-02 CAL161 - Jul 2, 06:15 UTCJul 2, 06:30 UTC15m
2026-07-02 CAL161 - Jul 2, 04:25 UTCJul 2, 05:00 UTC35m
2026-07-02 CAL160 TPE → ICN Jul 2, 00:30 UTCJul 2, 02:30 UTC2h 0m
2026-07-01 CAL161 - Jul 1, 04:20 UTCJul 1, 06:25 UTC2h 5m
2026-07-01 CAL160 TPE → ICN Jul 1, 00:40 UTCJul 1, 02:45 UTC2h 5m
2026-06-30 CAL161 - Jun 30, 04:20 UTCJun 30, 06:25 UTC2h 5m
2026-06-30 CAL160 TPE → ICN Jun 30, 00:30 UTCJun 30, 02:40 UTC2h 10m
2026-06-29 CAL105 - Jun 29, 12:20 UTCJun 29, 12:39 UTC20m
2026-06-29 CAL105 - Jun 29, 09:34 UTCJun 29, 10:55 UTC1h 20m
2026-06-29 CAL104 TPE → NRT Jun 29, 04:39 UTCJun 29, 07:25 UTC2h 45m
2026-06-28 CAL163 - Jun 28, 13:29 UTCJun 28, 13:55 UTC25m
2026-06-28 CAL163 - Jun 28, 11:45 UTCJun 28, 12:25 UTC40m
2026-06-28 CAL162 TPE → ICN Jun 28, 07:50 UTCJun 28, 09:50 UTC2h 0m
2026-06-28 CAL161 - Jun 28, 05:49 UTCJun 28, 06:05 UTC15m
2026-06-28 CAL161 - Jun 28, 04:05 UTCJun 28, 04:44 UTC40m
2026-06-28 CAL160 TPE → ICN Jun 28, 00:09 UTCJun 28, 02:14 UTC2h 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-18308 page for operator, model, and routing details .

Mode-S 8991B6 frequently asked

What is Mode-S code 8991B6?
8991B6 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18308.
Where is Mode-S 8991B6 registered?
Mode-S code 8991B6 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991B6 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 8991B6, octal 42310666, decimal 9,015,734.
What flights does 8991B6 operate?
Mode-S 8991B6 has broadcast 20 distinct callsigns, including CAL131, CAL792, CAL836, CAL161, CAL835.