Apparatus

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sensors Mode-S transponder

8991E4

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-58501 · AIRBUS A-350-900

Hex
8991E4
Octal
42310744
Decimal
9,015,780
Country
TW
Tail
B-58501
Type
A359
No current signal · last broadcast Jul 26, 19:30 UTC
Flights observed
248
Distinct callsigns
20
Country
TW
Last broadcast
Jul 26, 19:30 UTC

Last known position

Most recent position reported by Mode-S 8991E4.

Country allocation

The ICAO 24-bit address 8991E4 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
SJX032 STARLUX Airlines 23 2026-06-28
SJX001 - 21 2026-07-17
SJX031 - 19 2026-06-29
SJX823 STARLUX Airlines 16 2026-07-26
SJX002 - 15 2026-07-26
SJX851 - 11 2026-07-02
SJX822 STARLUX Airlines 11 2026-07-26
SJX771 - 11 2026-07-15
SJX850 - 10 2026-07-02
SJX870 STARLUX Airlines 9 2026-07-22
SJX742 - 9 2026-07-08
SJX741 - 9 2026-07-08
SJX011 STARLUX Airlines 9 2026-07-24
SJX010 - 9 2026-06-26
SJX772 - 8 2026-07-15
SJX012 STARLUX Airlines 8 2026-07-23
SJX009 - 7 2026-06-27
SJX871 STARLUX Airlines 6 2026-07-21
SJX803 - 5 2026-07-09
SJX802 - 4 2026-07-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SJX002 - Jul 26, 16:35 UTCJul 26, 19:30 UTC2h 55m
2026-07-26 SJX823 KIX → TPE Jul 26, 06:35 UTCJul 26, 09:00 UTC2h 25m
2026-07-26 SJX822 TPE → KIX Jul 26, 02:45 UTCJul 26, 05:00 UTC2h 15m
2026-07-24 SJX011 SFO → TPE Jul 24, 19:50 UTCJul 24, 20:05 UTC15m
2026-07-24 SJX011 SFO → TPE Jul 24, 08:25 UTCJul 24, 18:30 UTC10h 5m
2026-07-23 SJX012 TPE → SFO Jul 23, 16:55 UTCJul 24, 04:35 UTC11h 40m
2026-07-23 SJX841 FUK → TPE Jul 23, 07:25 UTCJul 23, 07:45 UTC20m
2026-07-23 SJX841 FUK → TPE Jul 23, 05:55 UTCJul 23, 06:10 UTC15m
2026-07-23 SJX840 TPE → FUK Jul 23, 01:55 UTCJul 23, 03:50 UTC1h 55m
2026-07-22 SJX870 TPE → OKA Jul 22, 04:20 UTCJul 22, 04:45 UTC25m
2026-07-21 SJX871 OKA → TPE Jul 21, 08:25 UTCJul 21, 08:50 UTC25m
2026-07-21 SJX870 TPE → OKA Jul 21, 04:35 UTCJul 21, 04:55 UTC20m
2026-07-20 SJX823 KIX → TPE Jul 20, 06:35 UTCJul 20, 08:55 UTC2h 20m
2026-07-20 SJX822 TPE → KIX Jul 20, 02:30 UTCJul 20, 04:55 UTC2h 25m
2026-07-19 SJX823 - Jul 19, 08:40 UTCJul 19, 09:05 UTC25m
2026-07-19 SJX823 - Jul 19, 06:50 UTCJul 19, 07:30 UTC40m
2026-07-19 SJX822 TPE → KIX Jul 19, 02:35 UTCJul 19, 04:55 UTC2h 20m
2026-07-17 SJX001 - Jul 17, 20:20 UTCJul 17, 20:40 UTC20m
2026-07-17 SJX001 - Jul 17, 08:20 UTCJul 17, 19:25 UTC11h 5m
2026-07-16 SJX002 - Jul 16, 17:54 UTCJul 17, 05:30 UTC11h 35m
2026-07-16 SJX002 - Jul 16, 17:10 UTCJul 16, 17:20 UTC10m
2026-07-16 SJX871 - Jul 16, 08:05 UTCJul 16, 08:20 UTC15m
2026-07-16 SJX870 - Jul 16, 05:10 UTCJul 16, 05:20 UTC10m
2026-07-16 SJX870 - Jul 16, 04:10 UTCJul 16, 04:25 UTC15m
2026-07-15 SJX772 - Jul 15, 06:25 UTCJul 15, 10:50 UTC4h 25m
2026-07-15 SJX771 - Jul 15, 03:50 UTCJul 15, 04:00 UTC10m
2026-07-15 SJX771 - Jul 15, 00:25 UTCJul 15, 01:20 UTC55m
2026-07-14 SJX011 SFO → TPE Jul 14, 08:40 UTCJul 14, 20:45 UTC12h 5m
2026-07-13 SJX012 TPE → SFO Jul 13, 16:40 UTCJul 14, 05:15 UTC12h 35m
2026-07-13 SJX772 - Jul 13, 06:40 UTCJul 13, 11:00 UTC4h 20m
2026-07-13 SJX771 - Jul 13, 04:00 UTCJul 13, 04:20 UTC20m
2026-07-13 SJX771 - Jul 13, 00:25 UTCJul 13, 01:10 UTC45m
2026-07-11 SJX3001 LAX → TPE Jul 11, 06:15 UTCJul 11, 18:55 UTC12h 40m
2026-07-09 SJX002 - Jul 9, 17:15 UTCJul 10, 05:00 UTC11h 45m
2026-07-09 SJX803 NRT → TPE Jul 9, 07:50 UTCJul 9, 10:40 UTC2h 50m
2026-07-09 SJX802 - Jul 9, 03:15 UTCJul 9, 06:10 UTC2h 55m
2026-07-08 SJX742 - Jul 8, 06:45 UTCJul 8, 10:15 UTC3h 30m
2026-07-08 SJX741 TPE → BKK Jul 8, 01:50 UTCJul 8, 05:00 UTC3h 10m
2026-07-07 SJX823 - Jul 7, 08:10 UTCJul 7, 08:30 UTC20m
2026-07-07 SJX823 - Jul 7, 06:25 UTCJul 7, 07:00 UTC35m
2026-07-07 SJX822 TPE → KIX Jul 7, 02:40 UTCJul 7, 04:55 UTC2h 15m
2026-07-06 SJX803 - Jul 6, 10:20 UTCJul 6, 10:45 UTC25m
2026-07-06 SJX803 - Jul 6, 07:55 UTCJul 6, 09:10 UTC1h 15m
2026-07-06 SJX802 TPE → NRT Jul 6, 03:25 UTCJul 6, 06:20 UTC2h 55m
2026-07-05 SJX803 NRT → TPE Jul 5, 07:55 UTCJul 5, 10:45 UTC2h 50m
2026-07-05 SJX802 TPE → NRT Jul 5, 03:05 UTCJul 5, 05:55 UTC2h 50m
2026-07-04 SJX803 NRT → TPE Jul 4, 07:45 UTCJul 4, 10:40 UTC2h 55m
2026-07-04 SJX802 - Jul 4, 03:00 UTCJul 4, 05:55 UTC2h 55m
2026-07-03 SJX823 - Jul 3, 08:25 UTCJul 3, 08:50 UTC25m
2026-07-03 SJX823 - Jul 3, 06:40 UTCJul 3, 07:15 UTC35m

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-58501 page for operator, model, and routing details .

Mode-S 8991E4 frequently asked

What is Mode-S code 8991E4?
8991E4 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-58501.
Where is Mode-S 8991E4 registered?
Mode-S code 8991E4 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991E4 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 19:30 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991E4, octal 42310744, decimal 9,015,780.
What flights does 8991E4 operate?
Mode-S 8991E4 has broadcast 20 distinct callsigns, including SJX032, SJX001, SJX031, SJX823, SJX002.