sensors Mode-S transponder

8990A9

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18617 · BOEING 737-800

Hex
8990A9
Octal
42310251
Decimal
9,015,465
Country
TW
Tail
B-18617
Type
B738
No current signal · last broadcast 3h ago
Flights observed
180
Distinct callsigns
20
Country
TW
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 8990A9.

Country allocation

The ICAO 24-bit address 8990A9 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
CAL851 China Airlines 9 2026-05-26
CAL129 China Airlines 9 2026-05-09
CAL852 China Airlines 7 2026-05-26
CAL128 China Airlines 7 2026-05-09
CAL794 China Airlines 6 2026-05-29
CAL189 China Airlines 6 2026-05-15
CAL151 China Airlines 6 2026-05-27
CAL150 China Airlines 6 2026-05-26
CAL793 China Airlines 5 2026-05-29
CAL123 China Airlines 5 2026-05-13
CAL113 China Airlines 5 2026-05-22
CAL112 China Airlines 5 2026-05-22
CAL109 China Airlines 5 2026-05-28
CAL764 China Airlines 4 2026-04-14
CAL122 China Airlines 4 2026-05-13
CAL107 China Airlines 4 2026-05-28
CAL910 China Airlines 3 2026-04-27
CAL787 China Airlines 3 2026-05-29
CAL763 - 3 2026-04-14
CAL756 China Airlines 3 2026-04-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 CAL787 TPE → DAD May 29, 23:30 UTCMay 30, 00:30 UTC1h 0m
2026-05-29 CAL794 HAN → TPE May 29, 11:05 UTCMay 29, 13:25 UTC2h 20m
2026-05-29 CAL793 TPE → HAN May 29, 06:45 UTCMay 29, 09:10 UTC2h 25m
2026-05-29 CAL279 TAK → TPE May 29, 04:45 UTCMay 29, 05:10 UTC25m
2026-05-29 CAL279 TAK → TPE May 29, 02:45 UTCMay 29, 03:15 UTC30m
2026-05-28 CAL278 TPE → TAK May 28, 23:00 UTCMay 29, 01:05 UTC2h 5m
2026-05-28 CAL109 NRT → TPE May 28, 14:05 UTCMay 28, 14:30 UTC25m
2026-05-28 CAL109 NRT → TPE May 28, 11:30 UTCMay 28, 12:45 UTC1h 15m
2026-05-28 CAL108 TPE → NRT May 28, 06:50 UTCMay 28, 09:50 UTC3h 0m
2026-05-28 CAL107 NRT → TPE May 28, 00:55 UTCMay 28, 04:00 UTC3h 5m
2026-05-27 CAL106 TPE → NRT May 27, 08:35 UTCMay 27, 11:35 UTC3h 0m
2026-05-27 CAL151 NGO → TPE May 27, 01:19 UTCMay 27, 03:45 UTC2h 25m
2026-05-26 CAL150 TPE → NGO May 26, 09:40 UTCMay 26, 12:05 UTC2h 25m
2026-05-26 CAL852 CNX → TPE May 26, 04:45 UTCMay 26, 08:10 UTC3h 25m
2026-05-26 CAL851 TPE → CNX May 26, 00:04 UTCMay 26, 03:19 UTC3h 15m
2026-05-25 CAL194 TPE → KMJ May 25, 07:00 UTCMay 25, 12:00 UTC5h 0m
2026-05-25 CAL151 NGO → TPE May 25, 03:25 UTCMay 25, 03:55 UTC30m
2026-05-24 CAL150 TPE → NGO May 24, 09:50 UTCMay 24, 12:10 UTC2h 20m
2026-05-24 CAL153 KIX → TPE May 24, 05:20 UTCMay 24, 08:15 UTC2h 55m
2026-05-24 CAL152 TPE → KIX May 24, 01:10 UTCMay 24, 03:25 UTC2h 15m
2026-05-23 CAL186 TPE → PUS May 23, 08:10 UTCMay 23, 13:40 UTC5h 30m
2026-05-22 CAL787 TPE → DAD May 22, 23:30 UTCMay 23, 05:25 UTC5h 54m
2026-05-22 CAL109 NRT → TPE May 22, 14:45 UTCMay 22, 15:15 UTC30m
2026-05-22 CAL109 NRT → TPE May 22, 12:10 UTCMay 22, 13:20 UTC1h 10m
2026-05-22 CAL108 TPE → NRT May 22, 07:40 UTCMay 22, 10:30 UTC2h 50m
2026-05-22 CAL113 HIJ → TPE May 22, 05:10 UTCMay 22, 05:30 UTC20m
2026-05-22 CAL113 HIJ → TPE May 22, 03:15 UTCMay 22, 03:35 UTC20m
2026-05-22 CAL112 TPE → HIJ May 22, 01:05 UTCMay 22, 01:25 UTC20m
2026-05-21 CAL112 TPE → HIJ May 21, 23:25 UTCMay 21, 23:45 UTC20m
2026-05-21 CAL187 PUS → TPE May 21, 12:55 UTCMay 21, 13:25 UTC30m
2026-05-21 CAL186 TPE → PUS May 21, 08:20 UTCMay 21, 08:40 UTC20m
2026-05-21 CAL2171 TOY → TPE May 21, 03:40 UTCMay 21, 06:40 UTC3h 0m
2026-05-20 CAL2170 TPE → TOY May 20, 22:30 UTCMay 21, 00:55 UTC2h 25m
2026-05-20 CAL836 BKK → TPE May 20, 10:50 UTCMay 20, 14:15 UTC3h 25m
2026-05-20 CAL835 TPE → BKK May 20, 05:55 UTCMay 20, 09:10 UTC3h 15m
2026-05-20 CAL107 NRT → TPE May 20, 01:05 UTCMay 20, 04:05 UTC3h 0m
2026-05-19 CAL106 TPE → NRT May 19, 09:25 UTCMay 19, 12:30 UTC3h 5m
2026-05-19 CAL151 NGO → TPE May 19, 01:10 UTCMay 19, 03:35 UTC2h 25m
2026-05-18 CAL150 TPE → NGO May 18, 09:25 UTCMay 18, 12:00 UTC2h 35m
2026-05-18 CAL705 TPE → CEB May 18, 00:35 UTCMay 18, 06:45 UTC6h 10m
2026-05-17 CAL163 ICN → TPE May 17, 11:40 UTCMay 17, 13:45 UTC2h 5m
2026-05-17 CAL162 TPE → ICN May 17, 07:55 UTCMay 17, 10:00 UTC2h 5m
2026-05-17 CAL155 NGO → TPE May 17, 03:40 UTCMay 17, 06:05 UTC2h 25m
2026-05-16 CAL154 TPE → NGO May 16, 23:40 UTCMay 17, 02:00 UTC2h 20m
2026-05-16 CAL794 HAN → TPE May 16, 07:01 UTCMay 16, 13:35 UTC6h 35m
2026-05-16 CAL602 HKG → TPE May 16, 02:40 UTCMay 16, 04:05 UTC1h 25m
2026-05-16 CAL601 TPE → HKG May 16, 01:00 UTCMay 16, 01:20 UTC20m
2026-05-15 CAL601 TPE → HKG May 15, 23:55 UTCMay 16, 00:25 UTC30m
2026-05-15 CAL789 TPE → DAD May 15, 07:10 UTCMay 15, 13:15 UTC6h 5m
2026-05-15 CAL189 PUS → TPE May 15, 00:05 UTCMay 15, 05:10 UTC5h 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-18617 page for operator, model, and routing details .

Mode-S 8990A9 frequently asked

What is Mode-S code 8990A9?
8990A9 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18617.
Where is Mode-S 8990A9 registered?
Mode-S code 8990A9 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8990A9 broadcasting right now?
No active broadcast right now. Last signal was 3h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8990A9, octal 42310251, decimal 9,015,465.
What flights does 8990A9 operate?
Mode-S 8990A9 has broadcast 20 distinct callsigns, including CAL851, CAL129, CAL852, CAL128, CAL794.