Apparatus

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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
Broadcasting now · callsign MDA212 · 6,650 ft
Flights observed
255
Distinct callsigns
20
Country
TW
Last broadcast
3h ago

Current position

8990A1 is currently broadcasting. Map zoomed to live position.

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

Callsign Airline Flights Last seen
CAL840 - 15 2026-06-16
CAL133 - 15 2026-06-15
CAL915 China Airlines 14 2026-05-23
CAL839 - 14 2026-06-16
CAL132 - 13 2026-06-21
CAL586 - 12 2026-06-21
CAL199 - 12 2026-06-17
CAL139 - 11 2026-06-19
CAL585 - 10 2026-06-21
CAL198 - 10 2026-06-16
CAL916 China Airlines 9 2026-05-23
CAL138 - 8 2026-06-19
CAL167 China Airlines 7 2026-06-10
CAL923 China Airlines 5 2026-05-21
CAL602 China Airlines 5 2026-05-22
CAL601 China Airlines 5 2026-05-21
CAL581 China Airlines 5 2026-06-15
CAL924 China Airlines 3 2026-05-21
CAL166 China Airlines 3 2026-06-09
MDA354 - 2 2026-06-19

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 MDA211 - Jul 14, 23:05 UTCJul 14, 23:25 UTC20m
2026-07-14 MDA1282 - Jul 14, 13:15 UTCJul 14, 13:45 UTC30m
2026-07-14 MDA773 - Jul 14, 11:15 UTCJul 14, 11:35 UTC20m
2026-07-14 MDA772 - Jul 14, 09:30 UTCJul 14, 09:50 UTC20m
2026-07-14 MDA771 - Jul 14, 07:45 UTCJul 14, 08:00 UTC15m
2026-07-14 CAL7852 - Jul 14, 06:05 UTCJul 14, 06:25 UTC20m
2026-07-12 TEST1234 TPE → TPE Jul 12, 01:35 UTCJul 12, 01:40 UTC5m
2026-06-21 CAL7842 KHH → TPE Jun 21, 13:44 UTCJun 21, 14:34 UTC50m
2026-06-21 CAL132 KHH → KHH Jun 21, 08:04 UTCJun 21, 12:19 UTC4h 15m
2026-06-21 CAL586 - Jun 21, 03:40 UTCJun 21, 05:04 UTC1h 25m
2026-06-21 CAL585 - Jun 21, 00:29 UTCJun 21, 01:35 UTC1h 5m
2026-06-20 CAL132 KHH → KHH Jun 20, 07:59 UTCJun 20, 12:09 UTC4h 10m
2026-06-19 MDA354 MZG → KHH Jun 19, 12:09 UTCJun 19, 12:34 UTC25m
2026-06-19 MDA353 KHH → MZG Jun 19, 10:39 UTCJun 19, 11:04 UTC25m
2026-06-19 MDA352 MZG → KHH Jun 19, 09:04 UTCJun 19, 09:24 UTC20m
2026-06-19 MDA351 KHH → MZG Jun 19, 07:39 UTCJun 19, 08:09 UTC30m
2026-06-19 CAL139 - Jun 19, 03:15 UTCJun 19, 05:24 UTC2h 10m
2026-06-19 CAL138 - Jun 19, 01:10 UTCJun 19, 01:24 UTC15m
2026-06-18 CAL138 - Jun 18, 23:25 UTCJun 19, 00:00 UTC35m
2026-06-18 CAL586 - Jun 18, 09:00 UTCJun 18, 09:20 UTC20m
2026-06-18 CAL586 - Jun 18, 08:15 UTCJun 18, 08:25 UTC10m
2026-06-18 CAL585 - Jun 18, 01:35 UTCJun 18, 01:50 UTC15m
2026-06-18 CAL585 - Jun 18, 00:40 UTCJun 18, 01:00 UTC20m
2026-06-17 CAL132 KHH → KHH Jun 17, 08:00 UTCJun 17, 12:20 UTC4h 20m
2026-06-17 CAL199 - Jun 17, 04:45 UTCJun 17, 05:40 UTC55m
2026-06-16 CAL198 - Jun 16, 23:40 UTCJun 17, 00:20 UTC40m
2026-06-16 CAL840 - Jun 16, 14:20 UTCJun 16, 14:39 UTC20m
2026-06-16 CAL840 - Jun 16, 11:35 UTCJun 16, 12:05 UTC30m
2026-06-16 CAL839 - Jun 16, 07:15 UTCJun 16, 10:15 UTC3h 0m
2026-06-15 CAL581 KHH → PVG Jun 15, 23:35 UTCJun 16, 04:45 UTC5h 10m
2026-06-15 CAL133 KHH → KHH Jun 15, 08:00 UTCJun 15, 12:49 UTC4h 50m
2026-06-15 CAL199 - Jun 15, 05:00 UTCJun 15, 05:50 UTC50m
2026-06-15 CAL198 - Jun 15, 01:35 UTCJun 15, 01:50 UTC15m
2026-06-14 CAL198 - Jun 14, 23:35 UTCJun 15, 00:24 UTC50m
2026-06-14 CAL133 KHH → KHH Jun 14, 08:10 UTCJun 14, 12:50 UTC4h 40m
2026-06-14 CAL586 SZX → KHH Jun 14, 04:35 UTCJun 14, 04:55 UTC20m
2026-06-14 CAL586 SZX → KHH Jun 14, 03:45 UTCJun 14, 04:05 UTC20m
2026-06-14 CAL585 KHH → SZX Jun 14, 01:30 UTCJun 14, 01:40 UTC10m
2026-06-14 CAL585 KHH → SZX Jun 14, 00:30 UTCJun 14, 00:50 UTC20m
2026-06-13 CAL840 BKK → KHH Jun 13, 11:30 UTCJun 13, 14:30 UTC3h 0m
2026-06-13 CAL839 - Jun 13, 06:40 UTCJun 13, 09:40 UTC3h 0m
2026-06-12 CAL581 KHH → PVG Jun 12, 23:05 UTCJun 13, 04:50 UTC5h 44m
2026-06-12 CAL840 BKK → KHH Jun 12, 11:20 UTCJun 12, 14:20 UTC3h 0m
2026-06-12 CAL839 KHH → BKK Jun 12, 07:00 UTCJun 12, 10:00 UTC3h 0m
2026-06-12 CAL139 FUK → KHH Jun 12, 04:45 UTCJun 12, 05:35 UTC50m
2026-06-12 CAL139 FUK → KHH Jun 12, 03:15 UTCJun 12, 03:25 UTC10m
2026-06-11 CAL138 KHH → FUK Jun 11, 23:30 UTCJun 12, 00:15 UTC45m
2026-06-11 CAL840 BKK → KHH Jun 11, 11:35 UTCJun 11, 14:40 UTC3h 5m
2026-06-11 CAL839 KHH → BKK Jun 11, 06:45 UTCJun 11, 09:50 UTC3h 5m
2026-06-11 CAL586 SZX → KHH Jun 11, 04:25 UTCJun 11, 04:40 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-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?
Yes. Mode-S 8990A1 is currently airborne.
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 CAL840, CAL133, CAL915, CAL839, CAL132.