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 19h ago
Flights observed
105
Distinct callsigns
20
Country
TW
Last broadcast
19h 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 China Airlines 14 2026-05-17
CAL130 China Airlines 9 2026-05-17
CAL151 China Airlines 8 2026-05-01
CAL836 China Airlines 7 2026-05-22
MDA991 - 5 2026-05-23
CAL835 China Airlines 5 2026-05-22
CAL521 China Airlines 5 2026-05-28
CAL150 China Airlines 5 2026-04-30
CAL792 China Airlines 3 2026-05-27
CAL522 China Airlines 3 2026-05-28
CAL111 China Airlines 3 2026-05-12
MDA992 - 2 2026-04-25
CAL919 China Airlines 2 2026-04-23
CAL832 China Airlines 2 2026-05-29
CAL831 China Airlines 2 2026-05-29
CAL783 China Airlines 2 2026-04-15
CAL704 China Airlines 2 2026-05-14
CAL703 China Airlines 2 2026-05-14
CAL702 China Airlines 2 2026-05-28
CAL701 China Airlines 2 2026-05-27

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 CAL832 BKK → TPE May 29, 07:00 UTCMay 29, 10:10 UTC3h 10m
2026-05-29 CAL831 TPE → BKK May 29, 02:10 UTCMay 29, 05:25 UTC3h 15m
2026-05-28 CAL522 CAN → TPE May 28, 10:15 UTCMay 28, 11:45 UTC1h 30m
2026-05-28 CAL521 TPE → CAN May 28, 07:25 UTCMay 28, 07:35 UTC10m
2026-05-28 CAL521 TPE → CAN May 28, 06:25 UTCMay 28, 06:55 UTC30m
2026-05-28 CAL702 MNL → TPE May 28, 03:00 UTCMay 28, 04:45 UTC1h 45m
2026-05-27 CAL701 TPE → MNL May 27, 23:40 UTCMay 28, 01:30 UTC1h 50m
2026-05-27 CAL792 HAN → TPE May 27, 01:05 UTCMay 27, 07:40 UTC6h 35m
2026-05-26 CAL552 CTU → TPE May 26, 01:00 UTCMay 26, 08:39 UTC7h 40m
2026-05-24 CAL552 CTU → TPE May 24, 01:00 UTCMay 24, 08:45 UTC7h 45m
2026-05-23 CAL522 CAN → TPE May 23, 10:40 UTCMay 23, 12:10 UTC1h 30m
2026-05-23 CAL521 TPE → CAN May 23, 08:10 UTCMay 23, 08:25 UTC15m
2026-05-23 CAL521 TPE → CAN May 23, 07:10 UTCMay 23, 07:40 UTC30m
2026-05-23 MDA991 TPE → TPE May 23, 01:15 UTCMay 23, 05:30 UTC4h 14m
2026-05-22 CAL836 BKK → TPE May 22, 10:45 UTCMay 22, 14:05 UTC3h 20m
2026-05-22 CAL835 TPE → BKK May 22, 05:50 UTCMay 22, 09:05 UTC3h 15m
2026-05-21 CAL522 CAN → TPE May 21, 10:35 UTCMay 21, 12:00 UTC1h 25m
2026-05-21 CAL521 TPE → CAN May 21, 06:30 UTCMay 21, 07:40 UTC1h 10m
2026-05-21 CAL702 MNL → TPE May 21, 03:00 UTCMay 21, 04:40 UTC1h 40m
2026-05-20 CAL701 TPE → MNL May 20, 23:50 UTCMay 21, 01:35 UTC1h 45m
2026-05-20 CAL101 NRT → TPE May 20, 08:45 UTCMay 20, 09:15 UTC30m
2026-05-20 CAL101 NRT → TPE May 20, 06:10 UTCMay 20, 07:25 UTC1h 15m
2026-05-20 CAL100 TPE → NRT May 20, 01:15 UTCMay 20, 04:05 UTC2h 50m
2026-05-17 CAL131 CTS → TPE May 17, 09:45 UTCMay 17, 10:10 UTC25m
2026-05-17 CAL131 CTS → TPE May 17, 06:45 UTCMay 17, 08:35 UTC1h 50m
2026-05-17 CAL130 TPE → CTS May 17, 00:55 UTCMay 17, 04:30 UTC3h 35m
2026-05-15 MDA991 TPE → TPE May 15, 01:05 UTCMay 15, 05:00 UTC3h 55m
2026-05-14 CAL704 MNL → TPE May 14, 09:10 UTCMay 14, 10:50 UTC1h 40m
2026-05-14 CAL703 TPE → MNL May 14, 05:45 UTCMay 14, 07:40 UTC1h 55m
2026-05-12 CAL111 FUK → TPE May 12, 04:20 UTCMay 12, 04:35 UTC15m
2026-05-06 CAL131 CTS → TPE May 6, 09:50 UTCMay 6, 10:10 UTC20m
2026-05-06 CAL131 CTS → TPE May 6, 06:20 UTCMay 6, 08:30 UTC2h 10m
2026-05-06 CAL130 TPE → CTS May 6, 01:15 UTCMay 6, 04:20 UTC3h 5m
2026-05-05 CAL131 CTS → TPE May 5, 10:05 UTCMay 5, 10:25 UTC20m
2026-05-05 CAL131 CTS → TPE May 5, 06:20 UTCMay 5, 08:35 UTC2h 15m
2026-05-05 CAL130 TPE → CTS May 5, 01:15 UTCMay 5, 04:25 UTC3h 10m
2026-05-04 CAL131 CTS → TPE May 4, 10:25 UTCMay 4, 10:45 UTC20m
2026-05-04 CAL131 CTS → TPE May 4, 06:15 UTCMay 4, 08:50 UTC2h 35m
2026-05-04 CAL130 TPE → CTS May 4, 02:25 UTCMay 4, 04:09 UTC1h 45m
2026-05-04 CAL130 TPE → CTS May 4, 01:05 UTCMay 4, 01:15 UTC10m
2026-05-03 CAL131 CTS → TPE May 3, 10:20 UTCMay 3, 10:35 UTC15m
2026-05-03 CAL131 CTS → TPE May 3, 06:40 UTCMay 3, 08:45 UTC2h 5m
2026-05-03 CAL130 TPE → CTS May 3, 00:55 UTCMay 3, 04:10 UTC3h 14m
2026-05-02 CAL111 FUK → TPE May 2, 04:15 UTCMay 2, 04:30 UTC15m
2026-05-02 CAL111 FUK → TPE May 2, 02:40 UTCMay 2, 02:50 UTC10m
2026-05-01 CAL110 TPE → FUK May 1, 23:15 UTCMay 1, 23:45 UTC30m
2026-05-01 CAL836 BKK → TPE May 1, 11:10 UTCMay 1, 14:40 UTC3h 30m
2026-05-01 CAL835 TPE → BKK May 1, 06:00 UTCMay 1, 09:30 UTC3h 30m
2026-05-01 CAL151 NGO → TPE May 1, 03:50 UTCMay 1, 04:10 UTC20m
2026-05-01 CAL151 NGO → TPE May 1, 02:00 UTCMay 1, 02:10 UTC10m

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 19h 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, CAL130, CAL151, CAL836, MDA991.