Apparatus

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sensors Mode-S transponder

8991BD

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18316 · AIRBUS A-330-300

Hex
8991BD
Octal
42310675
Decimal
9,015,741
Country
TW
Tail
B-18316
Type
A333
No current signal · last broadcast Jul 26, 11:35 UTC
Flights observed
407
Distinct callsigns
20
Country
TW
Last broadcast
Jul 26, 11:35 UTC

Last known position

Most recent position reported by Mode-S 8991BD.

Country allocation

The ICAO 24-bit address 8991BD 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
CAL173 - 36 2026-07-17
CAL172 - 24 2026-07-17
CAL702 China Airlines 23 2026-07-26
CAL701 China Airlines 23 2026-07-25
CAL117 China Airlines 19 2026-07-23
CAL110 China Airlines 17 2026-07-23
CAL111 China Airlines 15 2026-07-23
CAL116 China Airlines 14 2026-07-23
CAL153 - 13 2026-07-03
CAL105 - 13 2026-07-09
CAL834 China Airlines 12 2026-07-24
CAL833 China Airlines 12 2026-07-23
CAL152 China Airlines 12 2026-07-22
CAL919 China Airlines 11 2026-07-25
CAL131 - 11 2026-07-10
CAL104 - 11 2026-07-09
CAL920 China Airlines 9 2026-07-25
CAL161 - 9 2026-07-16
CAL704 - 8 2026-07-02
CAL703 - 8 2026-07-02

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 CAL528 SZX → TPE Jul 26, 10:10 UTCJul 26, 11:35 UTC1h 25m
2026-07-26 CAL527 TPE → SZX Jul 26, 06:50 UTCJul 26, 07:40 UTC50m
2026-07-26 CAL702 MNL → TPE Jul 26, 03:00 UTCJul 26, 04:35 UTC1h 35m
2026-07-25 CAL701 TPE → MNL Jul 25, 23:35 UTCJul 26, 01:20 UTC1h 45m
2026-07-25 CAL920 HKG → TPE Jul 25, 13:55 UTCJul 25, 15:30 UTC1h 35m
2026-07-25 CAL919 TPE → HKG Jul 25, 10:55 UTCJul 25, 12:15 UTC1h 20m
2026-07-25 MDA992 TPE → TPE Jul 25, 01:30 UTCJul 25, 06:30 UTC5h 0m
2026-07-24 CAL920 HKG → TPE Jul 24, 12:55 UTCJul 24, 15:10 UTC2h 15m
2026-07-24 CAL919 TPE → HKG Jul 24, 09:35 UTCJul 24, 10:45 UTC1h 10m
2026-07-24 CAL834 BKK → TPE Jul 24, 04:40 UTCJul 24, 07:45 UTC3h 5m
2026-07-23 CAL833 TPE → BKK Jul 23, 23:30 UTCJul 24, 02:50 UTC3h 20m
2026-07-23 CAL117 FUK → TPE Jul 23, 14:25 UTCJul 23, 14:45 UTC20m
2026-07-23 CAL117 FUK → TPE Jul 23, 12:55 UTCJul 23, 13:20 UTC25m
2026-07-23 CAL116 TPE → FUK Jul 23, 08:55 UTCJul 23, 10:35 UTC1h 40m
2026-07-23 CAL111 FUK → TPE Jul 23, 03:30 UTCJul 23, 04:35 UTC1h 5m
2026-07-23 CAL111 FUK → TPE Jul 23, 02:40 UTCJul 23, 02:50 UTC10m
2026-07-23 CAL110 TPE → FUK Jul 23, 00:25 UTCJul 23, 00:40 UTC15m
2026-07-22 CAL110 TPE → FUK Jul 22, 23:05 UTCJul 22, 23:30 UTC25m
2026-07-22 CAL152 TPE → KIX Jul 22, 03:20 UTCJul 22, 04:05 UTC45m
2026-07-22 CAL152 TPE → KIX Jul 22, 01:40 UTCJul 22, 02:00 UTC20m
2026-07-21 CAL552 CTU → TPE Jul 21, 01:35 UTCJul 21, 09:10 UTC7h 35m
2026-07-20 CAL834 BKK → TPE Jul 20, 06:50 UTCJul 20, 08:00 UTC1h 10m
2026-07-20 CAL834 BKK → TPE Jul 20, 04:40 UTCJul 20, 04:55 UTC15m
2026-07-20 CAL833 - Jul 20, 02:10 UTCJul 20, 02:25 UTC15m
2026-07-19 CAL833 - Jul 19, 23:20 UTCJul 20, 00:15 UTC55m
2026-07-19 CAL117 - Jul 19, 13:55 UTCJul 19, 14:20 UTC25m
2026-07-19 CAL117 - Jul 19, 12:30 UTCJul 19, 12:50 UTC20m
2026-07-19 CAL116 TPE → FUK Jul 19, 10:35 UTCJul 19, 10:55 UTC20m
2026-07-19 CAL116 TPE → FUK Jul 19, 09:15 UTCJul 19, 09:40 UTC25m
2026-07-19 CAL834 BKK → TPE Jul 19, 06:30 UTCJul 19, 07:20 UTC50m
2026-07-19 CAL834 BKK → TPE Jul 19, 04:05 UTCJul 19, 04:20 UTC15m
2026-07-19 CAL833 - Jul 19, 02:20 UTCJul 19, 02:35 UTC15m
2026-07-18 CAL833 - Jul 18, 23:20 UTCJul 19, 00:15 UTC55m
2026-07-18 MDA992 - Jul 18, 01:20 UTCJul 18, 05:10 UTC3h 51m
2026-07-17 CAL173 - Jul 17, 13:20 UTCJul 17, 13:35 UTC15m
2026-07-17 CAL173 - Jul 17, 11:20 UTCJul 17, 12:45 UTC1h 25m
2026-07-17 CAL172 TPE → KIX Jul 17, 07:14 UTCJul 17, 09:40 UTC2h 25m
2026-07-17 CAL702 MNL → TPE Jul 17, 02:59 UTCJul 17, 04:49 UTC1h 50m
2026-07-16 CAL701 TPE → MNL Jul 16, 23:35 UTCJul 17, 01:20 UTC1h 45m
2026-07-16 CAL163 - Jul 16, 13:45 UTCJul 16, 14:05 UTC20m
2026-07-16 CAL163 - Jul 16, 11:54 UTCJul 16, 12:40 UTC45m
2026-07-16 CAL162 - Jul 16, 09:40 UTCJul 16, 10:20 UTC40m
2026-07-16 CAL162 - Jul 16, 08:15 UTCJul 16, 08:30 UTC15m
2026-07-16 CAL161 - Jul 16, 06:05 UTCJul 16, 06:20 UTC15m
2026-07-16 CAL161 - Jul 16, 04:20 UTCJul 16, 05:05 UTC45m
2026-07-16 CAL160 - Jul 16, 00:25 UTCJul 16, 02:35 UTC2h 10m
2026-07-15 CAL101 - Jul 15, 08:30 UTCJul 15, 08:45 UTC15m
2026-07-15 CAL101 - Jul 15, 06:05 UTCJul 15, 07:25 UTC1h 20m
2026-07-15 CAL100 - Jul 15, 02:55 UTCJul 15, 04:20 UTC1h 25m
2026-07-15 CAL100 - Jul 15, 01:15 UTCJul 15, 01:30 UTC15m

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-18316 page for operator, model, and routing details .

Mode-S 8991BD frequently asked

What is Mode-S code 8991BD?
8991BD is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18316.
Where is Mode-S 8991BD registered?
Mode-S code 8991BD is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991BD broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 11:35 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991BD, octal 42310675, decimal 9,015,741.
What flights does 8991BD operate?
Mode-S 8991BD has broadcast 20 distinct callsigns, including CAL173, CAL172, CAL702, CAL701, CAL117.