sensors Mode-S transponder

8991DF

ICAO 24-bit transponder address · allocated to Taiwan

Currently assigned to B-58304 · AIRBUS A-330-900

Hex
8991DF
Octal
42310737
Decimal
9,015,775
Country
TW
Tail
B-58304
Type
A339
No current signal · last broadcast 15h ago
Flights observed
8
Distinct callsigns
6
Country
TW
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S 8991DF.

Country allocation

The ICAO 24-bit address 8991DF 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 6 distinct

Callsign Airline Flights Last seen
SJX851 - 2 2026-04-14
SJX839 - 2 2026-04-13
SJX850 - 1 2026-04-14
SJX847 STARLUX Airlines 1 2026-04-13
SJX846 STARLUX Airlines 1 2026-04-12
SJX838 - 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 SJX851 - Apr 14, 09:15 UTCApr 14, 09:30 UTC15m
2026-04-14 SJX851 - Apr 14, 07:35 UTCApr 14, 08:40 UTC1h 5m
2026-04-14 SJX850 - Apr 14, 05:15 UTCApr 14, 05:45 UTC30m
2026-04-13 SJX839 - Apr 13, 13:30 UTCApr 13, 13:45 UTC15m
2026-04-13 SJX839 - Apr 13, 11:10 UTCApr 13, 11:40 UTC30m
2026-04-13 SJX838 - Apr 13, 07:15 UTCApr 13, 07:30 UTC15m
2026-04-13 SJX847 KMJ → TPE Apr 13, 04:50 UTCApr 13, 05:00 UTC10m
2026-04-12 SJX846 TPE → KMJ Apr 12, 23:55 UTCApr 13, 00:35 UTC40m

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-58304 page for operator, model, and routing details .

Mode-S 8991DF frequently asked

What is Mode-S code 8991DF?
8991DF is an ICAO 24-bit transponder address. Allocated to Taiwan. Assigned to B-58304.
Where is Mode-S 8991DF registered?
Mode-S code 8991DF is allocated to Taiwan (TW). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8991DF broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8991DF, octal 42310737, decimal 9,015,775.
What flights does 8991DF operate?
Mode-S 8991DF has broadcast 6 distinct callsigns, including SJX851, SJX839, SJX850, SJX847, SJX846.