sensors Mode-S transponder

8990A1

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18652 · BOEING 737-800

Hex
8990A1
Octal
42310241
Decimal
9,015,457
Country
TW
Tail
B-18652
Type
B738
No current signal · last broadcast 5h ago
Flights observed
167
Distinct callsigns
20
Country
TW
Last broadcast
5h ago

Last known position

Most recent position reported by Mode-S 8990A1.

Country allocation

The ICAO 24-bit address 8990A1 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 CAL840 BKK → KHH May 30, 11:30 UTCMay 30, 14:35 UTC3h 5m
2026-05-30 CAL839 KHH → BKK May 30, 06:45 UTCMay 30, 10:00 UTC3h 15m
2026-05-29 CAL581 KHH → PVG May 29, 23:30 UTCMay 30, 05:00 UTC5h 30m
2026-05-29 CAL2132 KHH → OKA May 29, 07:05 UTCMay 29, 11:10 UTC4h 5m
2026-05-29 CAL139 FUK → KHH May 29, 04:45 UTCMay 29, 05:40 UTC55m
2026-05-29 CAL139 FUK → KHH May 29, 03:15 UTCMay 29, 03:25 UTC10m
2026-05-28 CAL138 KHH → FUK May 28, 23:05 UTCMay 28, 23:55 UTC50m
2026-05-28 CAL758 SIN → KHH May 28, 13:30 UTCMay 28, 14:30 UTC1h 0m
2026-05-28 CAL757 KHH → SIN May 28, 05:00 UTCMay 28, 08:35 UTC3h 35m
2026-05-28 MDA984 HKG → KHH May 28, 02:15 UTCMay 28, 03:25 UTC1h 10m
2026-05-27 MDA983 KHH → HKG May 27, 23:40 UTCMay 28, 00:40 UTC1h 0m
2026-05-27 CAL840 BKK → KHH May 27, 11:25 UTCMay 27, 14:25 UTC3h 0m
2026-05-27 CAL839 KHH → BKK May 27, 06:44 UTCMay 27, 09:40 UTC2h 55m
2026-05-27 MDA7845 TSA → KHH May 27, 04:09 UTCMay 27, 04:55 UTC45m
2026-05-27 MDA1264 KNH → TSA May 27, 02:34 UTCMay 27, 03:09 UTC35m
2026-05-27 MDA1263 TSA → KNH May 27, 00:34 UTCMay 27, 01:05 UTC30m
2026-05-26 MDA1270 KNH → TSA May 26, 06:49 UTCMay 26, 07:19 UTC30m
2026-05-26 MDA1269 TSA → KNH May 26, 04:30 UTCMay 26, 05:00 UTC30m
2026-05-26 MDA1264 KNH → TSA May 26, 02:44 UTCMay 26, 03:15 UTC30m
2026-05-26 MDA1263 TSA → KNH May 26, 00:39 UTCMay 26, 01:05 UTC25m
2026-05-25 MDA1276 KNH → TSA May 25, 11:40 UTCMay 25, 12:15 UTC35m
2026-05-25 MDA1275 TSA → KNH May 25, 09:25 UTCMay 25, 09:55 UTC30m
2026-05-25 CAL261 GMP → TSA May 25, 05:25 UTCMay 25, 07:25 UTC2h 0m
2026-05-25 CAL260 TSA → GMP May 25, 03:05 UTCMay 25, 03:40 UTC35m
2026-05-24 MDA798 MZG → RMQ May 24, 13:55 UTCMay 24, 14:20 UTC25m
2026-05-24 MDA355 KHH → MZG May 24, 12:30 UTCMay 24, 12:55 UTC25m
2026-05-24 MDA356 MZG → KHH May 24, 10:50 UTCMay 24, 11:10 UTC20m
2026-05-24 MDA797 RMQ → MZG May 24, 09:15 UTCMay 24, 09:35 UTC20m
2026-05-24 MDA1858 SGN → RMQ May 24, 00:30 UTCMay 24, 07:40 UTC7h 10m
2026-05-23 CAL7852 TPE → RMQ May 23, 22:35 UTCMay 23, 23:10 UTC35m
2026-05-23 CAL916 HKG → TPE May 23, 10:25 UTCMay 23, 11:50 UTC1h 25m
2026-05-23 CAL915 TPE → HKG May 23, 07:55 UTCMay 23, 08:20 UTC25m
2026-05-23 CAL915 TPE → HKG May 23, 06:50 UTCMay 23, 07:20 UTC30m
2026-05-22 CAL602 HKG → TPE May 22, 02:20 UTCMay 22, 03:40 UTC1h 20m
2026-05-21 CAL601 TPE → HKG May 21, 23:40 UTCMay 22, 00:55 UTC1h 15m
2026-05-21 CAL924 HKG → TPE May 21, 13:40 UTCMay 21, 15:00 UTC1h 20m
2026-05-21 CAL923 TPE → HKG May 21, 11:20 UTCMay 21, 11:35 UTC15m
2026-05-21 CAL923 TPE → HKG May 21, 10:20 UTCMay 21, 10:45 UTC25m
2026-05-21 MDA7846 TSA → TPE May 21, 08:05 UTCMay 21, 08:25 UTC20m
2026-05-21 MDA1270 KNH → TSA May 21, 06:20 UTCMay 21, 06:55 UTC35m
2026-05-21 MDA1269 TSA → KNH May 21, 04:20 UTCMay 21, 04:50 UTC30m
2026-05-21 MDA2382 MZG → TSA May 21, 01:30 UTCMay 21, 02:30 UTC1h 0m
2026-05-20 MDA2381 TSA → MZG May 20, 23:50 UTCMay 21, 00:25 UTC35m
2026-05-20 MDA218 WUH → TSA May 20, 11:50 UTCMay 20, 12:20 UTC30m
2026-05-20 MDA217 TSA → WUH May 20, 05:30 UTCMay 20, 05:55 UTC25m
2026-05-20 MDA212 FOC → TSA May 20, 03:00 UTCMay 20, 03:25 UTC25m
2026-05-19 MDA211 TSA → FOC May 19, 23:10 UTCMay 19, 23:40 UTC30m
2026-05-19 MDA7847 TPE → TSA May 19, 12:40 UTCMay 19, 12:50 UTC10m
2026-05-19 CAL916 HKG → TPE May 19, 10:00 UTCMay 19, 11:20 UTC1h 20m
2026-05-19 CAL915 TPE → HKG May 19, 07:10 UTCMay 19, 08:30 UTC1h 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-18652 page for operator, model, and routing details .

Mode-S 8990A1 frequently asked

What is Mode-S code 8990A1?
8990A1 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18652.
Where is Mode-S 8990A1 registered?
Mode-S code 8990A1 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8990A1 broadcasting right now?
No active broadcast right now. Last signal was 5h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8990A1, octal 42310241, decimal 9,015,457.
What flights does 8990A1 operate?
Mode-S 8990A1 has broadcast 20 distinct callsigns, including CAL915, CAL916, CAL133, CAL199, CAL132.