sensors Mode-S transponder

8991E6

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-58503 · AIRBUS A-350-900

Hex
8991E6
Octal
42310746
Decimal
9,015,782
Country
TW
Tail
B-58503
Type
A359
No current signal · last broadcast 13h ago
Flights observed
7
Distinct callsigns
4
Country
TW
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 8991E6.

Country allocation

The ICAO 24-bit address 8991E6 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 4 distinct

Callsign Airline Flights Last seen
SJX742 - 3 2026-04-14
SJX772 - 2 2026-04-13
SJX771 - 1 2026-04-13
SJX031 STARLUX Airlines 1 2026-04-12

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 SJX742 - Apr 14, 09:10 UTCApr 14, 09:45 UTC35m
2026-04-14 SJX742 - Apr 14, 08:45 UTCApr 14, 09:05 UTC20m
2026-04-14 SJX742 - Apr 14, 06:35 UTCApr 14, 06:50 UTC15m
2026-04-13 SJX772 - Apr 13, 09:15 UTCApr 13, 10:25 UTC1h 10m
2026-04-13 SJX772 - Apr 13, 06:15 UTCApr 13, 06:40 UTC25m
2026-04-13 SJX771 - Apr 13, 00:30 UTCApr 13, 01:30 UTC1h 0m
2026-04-12 SJX031 SEA → TPE Apr 12, 17:20 UTCApr 12, 18:35 UTC1h 15m

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-58503 page for operator, model, and routing details .

Mode-S 8991E6 frequently asked

What is Mode-S code 8991E6?
8991E6 is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-58503.
Where is Mode-S 8991E6 registered?
Mode-S code 8991E6 is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991E6 broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991E6, octal 42310746, decimal 9,015,782.
What flights does 8991E6 operate?
Mode-S 8991E6 has broadcast 4 distinct callsigns, including SJX742, SJX772, SJX771, SJX031.