Apparatus

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sensors Mode-S transponder

8990A4

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-18772 · BOEING 777-200LR

Hex
8990A4
Octal
42310244
Decimal
9,015,460
Country
TW
Tail
B-18772
Type
B77L
No current signal · last broadcast 42m ago
Flights observed
269
Distinct callsigns
20
Country
TW
Last broadcast
42m ago

Last known position

Most recent position reported by Mode-S 8990A4.

Country allocation

The ICAO 24-bit address 8990A4 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
CAL5381 - 30 2026-06-22
CAL5382 - 25 2026-06-21
CAL5346 - 22 2026-07-13
CAL5345 - 21 2026-07-13
CAL5309 - 17 2026-07-10
CAL5165 - 15 2026-07-05
CAL5310 - 13 2026-07-09
CAL5313 China Airlines 10 2026-07-08
CAL5166 - 10 2026-07-03
CAL5522 China Airlines 9 2026-05-19
CAL5312 China Airlines 8 2026-05-27
CAL5311 China Airlines 8 2026-05-28
CAL5142 China Airlines 7 2026-05-17
CAL5141 China Airlines 7 2026-05-18
CAL5314 - 6 2026-07-07
CAL5021 China Airlines 6 2026-05-18
CAL5162 China Airlines 4 2026-06-04
CAL5161 China Airlines 4 2026-06-04
CAL5116 China Airlines 4 2026-05-28
CAL5335 China Airlines 3 2026-06-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 CAL5345 - Jul 13, 16:25 UTCJul 14, 03:00 UTC10h 35m
2026-07-13 CAL5345 ATL → SFO Jul 13, 09:00 UTCJul 13, 13:10 UTC4h 10m
2026-07-13 CAL5346 SFO → ATL Jul 13, 02:40 UTCJul 13, 06:55 UTC4h 15m
2026-07-12 CAL5346 - Jul 12, 14:50 UTCJul 13, 01:10 UTC10h 20m
2026-07-12 CAL5346 - Jul 12, 13:25 UTCJul 12, 13:40 UTC15m
2026-07-12 CAL5321 - Jul 12, 00:55 UTCJul 12, 10:05 UTC9h 10m
2026-07-11 CAL5321 JFK → ANC Jul 11, 09:20 UTCJul 11, 16:25 UTC7h 5m
2026-07-10 CAL5322 ANC → JFK Jul 10, 22:50 UTCJul 11, 04:55 UTC6h 5m
2026-07-10 CAL5322 - Jul 10, 14:00 UTCJul 10, 21:40 UTC7h 40m
2026-07-10 CAL5322 - Jul 10, 12:25 UTCJul 10, 12:35 UTC10m
2026-07-10 CAL5309 - Jul 10, 09:10 UTCJul 10, 09:30 UTC20m
2026-07-10 CAL5309 - Jul 10, 00:25 UTCJul 10, 07:50 UTC7h 25m
2026-07-09 CAL5309 JFK → ANC Jul 9, 16:00 UTCJul 9, 22:45 UTC6h 45m
2026-07-09 CAL5310 YYZ → JFK Jul 9, 13:00 UTCJul 9, 14:05 UTC1h 5m
2026-07-09 CAL5310 - Jul 9, 05:30 UTCJul 9, 11:15 UTC5h 45m
2026-07-08 CAL5310 - Jul 8, 20:45 UTCJul 9, 04:05 UTC7h 20m
2026-07-08 CAL5310 - Jul 8, 19:20 UTCJul 8, 19:30 UTC10m
2026-07-08 CAL5313 ORD → NGO Jul 8, 10:50 UTCJul 8, 13:10 UTC2h 20m
2026-07-07 CAL5313 ORD → NGO Jul 7, 20:00 UTCJul 8, 08:35 UTC12h 35m
2026-07-07 CAL5314 - Jul 7, 06:10 UTCJul 7, 17:35 UTC11h 25m
2026-07-07 CAL5314 - Jul 7, 02:05 UTCJul 7, 04:15 UTC2h 10m
2026-07-06 CAL5345 SFO → TPE Jul 6, 10:40 UTCJul 6, 23:05 UTC12h 25m
2026-07-06 CAL5345 SFO → TPE Jul 6, 03:05 UTCJul 6, 07:30 UTC4h 25m
2026-07-05 CAL5346 - Jul 5, 20:50 UTCJul 6, 01:05 UTC4h 15m
2026-07-05 CAL5346 - Jul 5, 07:30 UTCJul 5, 18:40 UTC11h 10m
2026-07-05 CAL5165 - Jul 5, 03:20 UTCJul 5, 03:45 UTC25m
2026-07-05 CAL5165 - Jul 5, 01:20 UTCJul 5, 01:50 UTC30m
2026-07-04 CAL5165 - Jul 4, 11:30 UTCJul 4, 23:00 UTC11h 30m
2026-07-03 CAL5166 - Jul 3, 22:15 UTCJul 4, 08:15 UTC10h 0m
2026-07-03 CAL5166 - Jul 3, 20:30 UTCJul 3, 20:40 UTC10m
2026-07-03 CAL5309 - Jul 3, 11:25 UTCJul 3, 11:40 UTC15m
2026-07-03 CAL5309 - Jul 3, 01:40 UTCJul 3, 10:00 UTC8h 20m
2026-07-02 CAL5309 JFK → ANC Jul 2, 16:55 UTCJul 2, 23:40 UTC6h 45m
2026-07-02 CAL5310 YYZ → JFK Jul 2, 13:05 UTCJul 2, 14:05 UTC1h 0m
2026-07-02 CAL5310 ANC → YYZ Jul 2, 05:45 UTCJul 2, 11:35 UTC5h 50m
2026-07-01 CAL5310 - Jul 1, 19:35 UTCJul 2, 03:55 UTC8h 20m
2026-07-01 CAL5165 KIX → TPE Jul 1, 08:30 UTCJul 1, 10:55 UTC2h 25m
2026-06-30 CAL5165 - Jun 30, 17:40 UTCJul 1, 05:30 UTC11h 50m
2026-06-30 CAL5166 - Jun 30, 05:15 UTCJun 30, 14:50 UTC9h 35m
2026-06-30 CAL5166 - Jun 30, 03:25 UTCJun 30, 03:40 UTC15m
2026-06-29 CAL5345 SFO → TPE Jun 29, 11:25 UTCJun 30, 00:00 UTC12h 35m
2026-06-29 CAL5345 SFO → TPE Jun 29, 03:44 UTCJun 29, 08:09 UTC4h 25m
2026-06-28 CAL5346 SFO → ATL Jun 28, 21:55 UTCJun 29, 01:50 UTC3h 55m
2026-06-28 CAL5346 - Jun 28, 11:25 UTCJun 28, 20:19 UTC8h 55m
2026-06-28 CAL5346 - Jun 28, 09:39 UTCJun 28, 09:55 UTC15m
2026-06-28 CAL5165 - Jun 28, 06:44 UTCJun 28, 07:05 UTC20m
2026-06-28 CAL5165 - Jun 28, 04:35 UTCJun 28, 05:09 UTC35m
2026-06-27 CAL5165 - Jun 27, 14:05 UTCJun 28, 01:50 UTC11h 45m
2026-06-27 CAL5166 - Jun 27, 01:35 UTCJun 27, 11:35 UTC10h 0m
2026-06-27 CAL5166 - Jun 27, 00:05 UTCJun 27, 00:20 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-18772 page for operator, model, and routing details .

Mode-S 8990A4 frequently asked

What is Mode-S code 8990A4?
8990A4 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-18772.
Where is Mode-S 8990A4 registered?
Mode-S code 8990A4 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8990A4 broadcasting right now?
No active broadcast right now. Last signal was 42m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8990A4, octal 42310244, decimal 9,015,460.
What flights does 8990A4 operate?
Mode-S 8990A4 has broadcast 20 distinct callsigns, including CAL5381, CAL5382, CAL5346, CAL5345, CAL5309.