sensors Mode-S transponder

A91349

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N684NK · AIRBUS A-321 · operated by SPIRIT AIRLINES LLC

Hex
A91349
Octal
52211511
Decimal
11,080,521
Country
US
Tail
N684NK
Type
A321
No current signal · last broadcast 16h ago
Flights observed
10
Distinct callsigns
6
Country
US
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S A91349.

Country allocation

The ICAO 24-bit address A91349 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States 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
NKS992 - 3 2026-04-13
NKS991 Spirit Airlines 3 2026-04-13
NKS990 - 1 2026-04-13
NKS1711 - 1 2026-04-12
NKS1606 - 1 2026-04-13
NKS108 - 1 2026-04-14

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-14 NKS108 - Apr 14, 05:15 UTCApr 14, 06:35 UTC1h 20m
2026-04-13 NKS1606 MCO → ORD Apr 13, 20:40 UTCApr 13, 23:30 UTC2h 50m
2026-04-13 NKS992 - Apr 13, 16:15 UTCApr 13, 16:55 UTC40m
2026-04-13 NKS992 - Apr 13, 15:50 UTCApr 13, 16:55 UTC1h 5m
2026-04-13 NKS992 - Apr 13, 14:30 UTCApr 13, 16:15 UTC1h 45m
2026-04-13 NKS991 EWR → MYR Apr 13, 12:20 UTCApr 13, 12:45 UTC25m
2026-04-13 NKS991 EWR → MYR Apr 13, 11:55 UTCApr 13, 12:45 UTC50m
2026-04-13 NKS991 EWR → MYR Apr 13, 10:30 UTCApr 13, 12:15 UTC1h 45m
2026-04-13 NKS990 - Apr 13, 01:05 UTCApr 13, 03:10 UTC2h 5m
2026-04-12 NKS1711 - Apr 12, 17:15 UTCApr 12, 18:40 UTC1h 25m

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 N684NK page for operator, model, and routing details .

Mode-S A91349 frequently asked

What is Mode-S code A91349?
A91349 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N684NK.
Where is Mode-S A91349 registered?
Mode-S code A91349 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A91349 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A91349, octal 52211511, decimal 11,080,521.
What flights does A91349 operate?
Mode-S A91349 has broadcast 6 distinct callsigns, including NKS992, NKS991, NKS990, NKS1711, NKS1606.