sensors Mode-S transponder

8991B3

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18305 · AIRBUS A-330-300

Hex
8991B3
Octal
42310663
Decimal
9,015,731
Country
TW
Tail
B-18305
Type
A333
No current signal · last broadcast 5d ago
Flights observed
97
Distinct callsigns
20
Country
TW
Last broadcast
5d ago

Last known position

Most recent position reported by Mode-S 8991B3.

Country allocation

The ICAO 24-bit address 8991B3 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
CAL117 China Airlines 11 2026-05-15
CAL116 China Airlines 6 2026-05-15
CAL791 China Airlines 5 2026-05-15
CAL836 China Airlines 4 2026-05-08
CAL835 China Airlines 4 2026-05-08
CAL704 China Airlines 3 2026-05-16
CAL703 China Airlines 3 2026-05-16
CAL163 China Airlines 3 2026-05-10
CAL162 China Airlines 3 2026-05-10
CAL157 China Airlines 3 2026-04-19
CAL131 China Airlines 3 2026-05-11
CAL130 China Airlines 3 2026-05-11
CAL111 China Airlines 3 2026-05-16
CAL077 China Airlines 3 2026-05-24
CAL924 China Airlines 2 2026-05-03
CAL923 China Airlines 2 2026-05-03
CAL919 China Airlines 2 2026-04-25
CAL792 China Airlines 2 2026-05-12
CAL601 China Airlines 2 2026-05-02
CAL156 China Airlines 2 2026-04-19

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-24 CAL077 VIE → NOC May 24, 05:40 UTCMay 24, 08:15 UTC2h 35m
2026-05-22 CAL077 VIE → NOC May 22, 19:25 UTCMay 23, 06:30 UTC11h 5m
2026-05-22 CAL077 VIE → NOC May 22, 14:20 UTCMay 22, 17:35 UTC3h 15m
2026-05-16 CAL704 MNL → TPE May 16, 09:35 UTCMay 16, 11:21 UTC1h 45m
2026-05-16 CAL703 TPE → MNL May 16, 06:06 UTCMay 16, 07:55 UTC1h 50m
2026-05-16 CAL111 FUK → TPE May 16, 04:00 UTCMay 16, 04:25 UTC25m
2026-05-15 CAL110 TPE → FUK May 15, 23:10 UTCMay 15, 23:35 UTC25m
2026-05-15 CAL117 FUK → TPE May 15, 13:50 UTCMay 15, 14:15 UTC25m
2026-05-15 CAL117 FUK → TPE May 15, 12:25 UTCMay 15, 12:35 UTC10m
2026-05-15 CAL116 TPE → FUK May 15, 09:00 UTCMay 15, 09:20 UTC20m
2026-05-15 CAL791 TPE → HAN May 15, 00:40 UTCMay 15, 07:05 UTC6h 25m
2026-05-14 CAL155 NGO → TPE May 14, 04:10 UTCMay 14, 06:55 UTC2h 45m
2026-05-14 CAL154 TPE → NGO May 14, 00:00 UTCMay 14, 02:05 UTC2h 5m
2026-05-13 CAL101 NRT → TPE May 13, 08:40 UTCMay 13, 09:15 UTC35m
2026-05-13 CAL101 NRT → TPE May 13, 06:05 UTCMay 13, 07:10 UTC1h 5m
2026-05-13 CAL100 TPE → NRT May 13, 02:40 UTCMay 13, 03:55 UTC1h 15m
2026-05-13 CAL100 TPE → NRT May 13, 01:10 UTCMay 13, 01:25 UTC15m
2026-05-12 CAL792 HAN → TPE May 12, 05:55 UTCMay 12, 07:05 UTC1h 10m
2026-05-11 CAL131 CTS → TPE May 11, 10:10 UTCMay 11, 10:30 UTC20m
2026-05-11 CAL131 CTS → TPE May 11, 06:20 UTCMay 11, 08:20 UTC2h 0m
2026-05-11 CAL130 TPE → CTS May 11, 02:30 UTCMay 11, 04:15 UTC1h 45m
2026-05-11 CAL130 TPE → CTS May 11, 01:00 UTCMay 11, 01:15 UTC15m
2026-05-10 CAL163 ICN → TPE May 10, 11:50 UTCMay 10, 14:04 UTC2h 15m
2026-05-10 CAL162 TPE → ICN May 10, 07:55 UTCMay 10, 09:45 UTC1h 50m
2026-05-09 CAL791 TPE → HAN May 9, 01:05 UTCMay 9, 07:35 UTC6h 30m
2026-05-08 CAL836 BKK → TPE May 8, 11:49 UTCMay 8, 15:00 UTC3h 10m
2026-05-08 CAL835 TPE → BKK May 8, 05:54 UTCMay 8, 09:19 UTC3h 25m
2026-05-08 CAL121 OKA → TPE May 8, 04:04 UTCMay 8, 04:29 UTC25m
2026-05-08 CAL120 TPE → OKA May 8, 01:40 UTCMay 8, 01:49 UTC10m
2026-05-08 CAL120 TPE → OKA May 8, 00:49 UTCMay 8, 01:04 UTC15m
2026-05-07 CAL704 MNL → TPE May 7, 09:25 UTCMay 7, 10:55 UTC1h 30m
2026-05-07 CAL703 TPE → MNL May 7, 06:10 UTCMay 7, 07:55 UTC1h 45m
2026-05-06 CAL155 NGO → TPE May 6, 06:00 UTCMay 6, 06:20 UTC20m
2026-05-06 CAL154 TPE → NGO May 6, 00:05 UTCMay 6, 04:30 UTC4h 25m
2026-05-05 CAL117 FUK → TPE May 5, 14:30 UTCMay 5, 14:55 UTC25m
2026-05-05 CAL117 FUK → TPE May 5, 12:45 UTCMay 5, 12:55 UTC10m
2026-05-05 CAL116 TPE → FUK May 5, 09:45 UTCMay 5, 09:55 UTC10m
2026-05-05 CAL834 BKK → TPE May 5, 04:35 UTCMay 5, 07:55 UTC3h 20m
2026-05-04 CAL833 TPE → BKK May 4, 23:15 UTCMay 5, 02:50 UTC3h 35m
2026-05-04 CAL836 BKK → TPE May 4, 11:25 UTCMay 4, 14:50 UTC3h 25m
2026-05-04 CAL835 TPE → BKK May 4, 05:55 UTCMay 4, 09:45 UTC3h 50m
2026-05-03 CAL924 HKG → TPE May 3, 14:50 UTCMay 3, 16:05 UTC1h 15m
2026-05-03 CAL923 TPE → HKG May 3, 10:55 UTCMay 3, 12:30 UTC1h 35m
2026-05-03 CAL552 CTU → TPE May 3, 01:10 UTCMay 3, 08:30 UTC7h 19m
2026-05-02 CAL836 BKK → TPE May 2, 10:55 UTCMay 2, 14:25 UTC3h 30m
2026-05-02 CAL835 TPE → BKK May 2, 05:55 UTCMay 2, 09:20 UTC3h 25m
2026-05-02 CAL602 HKG → TPE May 2, 02:40 UTCMay 2, 04:00 UTC1h 20m
2026-05-02 CAL601 TPE → HKG May 2, 00:30 UTCMay 2, 00:55 UTC25m
2026-05-01 CAL601 TPE → HKG May 1, 23:30 UTCMay 1, 23:55 UTC25m
2026-05-01 CAL832 BKK → TPE May 1, 07:20 UTCMay 1, 10:25 UTC3h 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-18305 page for operator, model, and routing details .

Mode-S 8991B3 frequently asked

What is Mode-S code 8991B3?
8991B3 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18305.
Where is Mode-S 8991B3 registered?
Mode-S code 8991B3 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991B3 broadcasting right now?
No active broadcast right now. Last signal was 5d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991B3, octal 42310663, decimal 9,015,731.
What flights does 8991B3 operate?
Mode-S 8991B3 has broadcast 20 distinct callsigns, including CAL117, CAL116, CAL791, CAL836, CAL835.