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 1h ago
Flights observed
164
Distinct callsigns
20
Country
TW
Last broadcast
1h ago

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 China Airlines 14 2026-05-29
CAL172 China Airlines 9 2026-05-29
CAL153 China Airlines 9 2026-05-22
CAL104 China Airlines 9 2026-05-30
CAL105 China Airlines 8 2026-05-24
CAL702 China Airlines 7 2026-05-29
CAL701 China Airlines 7 2026-05-28
CAL117 China Airlines 7 2026-05-20
CAL152 China Airlines 6 2026-05-22
CAL836 China Airlines 5 2026-05-28
CAL835 China Airlines 5 2026-05-28
CAL131 China Airlines 5 2026-04-18
CAL130 China Airlines 5 2026-04-18
CAL111 China Airlines 5 2026-05-27
CAL116 China Airlines 4 2026-05-20
CAL110 China Airlines 4 2026-05-26
CAL920 China Airlines 3 2026-05-22
CAL919 China Airlines 3 2026-05-22
CAL834 China Airlines 3 2026-05-19
CAL833 China Airlines 3 2026-05-18

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 CAL104 TPE → NRT May 30, 06:00 UTCMay 30, 07:15 UTC1h 15m
2026-05-30 CAL104 TPE → NRT May 30, 04:35 UTCMay 30, 04:50 UTC15m
2026-05-29 CAL173 KIX → TPE May 29, 10:30 UTCMay 29, 12:50 UTC2h 20m
2026-05-29 CAL172 TPE → KIX May 29, 06:25 UTCMay 29, 08:30 UTC2h 5m
2026-05-29 CAL702 MNL → TPE May 29, 03:10 UTCMay 29, 04:50 UTC1h 40m
2026-05-28 CAL701 TPE → MNL May 28, 23:50 UTCMay 29, 01:35 UTC1h 45m
2026-05-28 CAL836 BKK → TPE May 28, 11:00 UTCMay 28, 14:20 UTC3h 20m
2026-05-28 CAL835 TPE → BKK May 28, 05:55 UTCMay 28, 09:15 UTC3h 20m
2026-05-28 CAL121 OKA → TPE May 28, 03:55 UTCMay 28, 04:20 UTC25m
2026-05-28 CAL120 TPE → OKA May 28, 00:35 UTCMay 28, 01:05 UTC30m
2026-05-27 CAL704 MNL → TPE May 27, 09:55 UTCMay 27, 11:40 UTC1h 45m
2026-05-27 CAL703 TPE → MNL May 27, 06:15 UTCMay 27, 08:15 UTC2h 0m
2026-05-27 CAL111 FUK → TPE May 27, 04:19 UTCMay 27, 04:49 UTC30m
2026-05-27 CAL111 FUK → TPE May 27, 02:54 UTCMay 27, 03:04 UTC10m
2026-05-26 CAL110 TPE → FUK May 26, 23:05 UTCMay 26, 23:29 UTC25m
2026-05-26 CAL109 NRT → TPE May 26, 14:09 UTCMay 26, 14:35 UTC25m
2026-05-26 CAL109 NRT → TPE May 26, 11:34 UTCMay 26, 12:50 UTC1h 15m
2026-05-26 CAL108 TPE → NRT May 26, 06:59 UTCMay 26, 09:55 UTC2h 55m
2026-05-24 CAL105 NRT → TPE May 24, 12:20 UTCMay 24, 12:50 UTC30m
2026-05-24 CAL105 NRT → TPE May 24, 09:45 UTCMay 24, 10:55 UTC1h 10m
2026-05-24 CAL104 TPE → NRT May 24, 04:45 UTCMay 24, 07:30 UTC2h 45m
2026-05-23 CAL173 KIX → TPE May 23, 10:40 UTCMay 23, 13:10 UTC2h 30m
2026-05-23 CAL172 TPE → KIX May 23, 06:45 UTCMay 23, 09:00 UTC2h 15m
2026-05-23 CAL904 HKG → TPE May 23, 03:30 UTCMay 23, 05:00 UTC1h 30m
2026-05-23 CAL903 TPE → HKG May 23, 01:30 UTCMay 23, 01:40 UTC10m
2026-05-23 CAL903 TPE → HKG May 23, 00:25 UTCMay 23, 00:50 UTC25m
2026-05-22 CAL920 HKG → TPE May 22, 12:50 UTCMay 22, 14:15 UTC1h 25m
2026-05-22 CAL919 TPE → HKG May 22, 10:45 UTCMay 22, 10:55 UTC10m
2026-05-22 CAL919 TPE → HKG May 22, 09:40 UTCMay 22, 10:10 UTC30m
2026-05-22 CAL153 KIX → TPE May 22, 07:50 UTCMay 22, 08:05 UTC15m
2026-05-22 CAL153 KIX → TPE May 22, 05:45 UTCMay 22, 06:20 UTC35m
2026-05-22 CAL152 TPE → KIX May 22, 01:15 UTCMay 22, 03:30 UTC2h 15m
2026-05-21 CAL836 BKK → TPE May 21, 11:05 UTCMay 21, 14:30 UTC3h 25m
2026-05-21 CAL835 TPE → BKK May 21, 06:15 UTCMay 21, 09:25 UTC3h 10m
2026-05-21 CAL111 FUK → TPE May 21, 04:20 UTCMay 21, 04:40 UTC20m
2026-05-20 CAL110 TPE → FUK May 20, 23:05 UTCMay 20, 23:25 UTC20m
2026-05-20 CAL117 FUK → TPE May 20, 14:05 UTCMay 20, 14:25 UTC20m
2026-05-20 CAL116 TPE → FUK May 20, 08:55 UTCMay 20, 09:15 UTC20m
2026-05-20 CAL792 HAN → TPE May 20, 06:50 UTCMay 20, 07:20 UTC30m
2026-05-20 CAL791 TPE → HAN May 20, 00:55 UTCMay 20, 06:15 UTC5h 21m
2026-05-19 CAL117 FUK → TPE May 19, 14:00 UTCMay 19, 14:25 UTC25m
2026-05-19 CAL117 FUK → TPE May 19, 12:30 UTCMay 19, 12:40 UTC10m
2026-05-19 CAL116 TPE → FUK May 19, 09:15 UTCMay 19, 09:40 UTC25m
2026-05-19 CAL834 BKK → TPE May 19, 04:15 UTCMay 19, 07:35 UTC3h 20m
2026-05-18 CAL833 TPE → BKK May 18, 23:25 UTCMay 19, 02:35 UTC3h 10m
2026-05-18 CAL836 BKK → TPE May 18, 10:40 UTCMay 18, 13:55 UTC3h 15m
2026-05-18 CAL835 TPE → BKK May 18, 05:45 UTCMay 18, 08:55 UTC3h 10m
2026-05-17 CAL153 KIX → TPE May 17, 07:15 UTCMay 17, 07:40 UTC25m
2026-05-17 CAL153 KIX → TPE May 17, 05:25 UTCMay 17, 05:55 UTC30m
2026-05-17 CAL152 TPE → KIX May 17, 01:15 UTCMay 17, 03:35 UTC2h 20m

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 1h ago.
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, CAL153, CAL104, CAL105.