sensors Mode-S transponder

A549E9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N44SW · CESSNA 550 Citation S2 · operated by STEEL WAREHOUSE COMPANY LLC

Hex
A549E9
Octal
51244751
Decimal
10,832,361
Country
US
Tail
N44SW
Type
C550
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A549E9.

Country allocation

The ICAO 24-bit address A549E9 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 1 distinct

Callsign Airline Flights Last seen
N44SW - 6 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 N44SW - Apr 13, 20:25 UTCApr 13, 22:35 UTC2h 10m
2026-04-13 N44SW - Apr 13, 18:30 UTCApr 13, 19:05 UTC35m
2026-04-13 N44SW - Apr 13, 16:15 UTCApr 13, 17:30 UTC1h 15m
2026-04-13 N44SW - Apr 13, 15:55 UTCApr 13, 16:15 UTC20m
2026-04-12 N44SW - Apr 12, 19:50 UTCApr 12, 20:15 UTC25m
2026-04-12 N44SW - Apr 12, 17:30 UTCApr 12, 19:05 UTC1h 35m

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 N44SW page for operator, model, and routing details .

Mode-S A549E9 frequently asked

What is Mode-S code A549E9?
A549E9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N44SW.
Where is Mode-S A549E9 registered?
Mode-S code A549E9 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 A549E9 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A549E9, octal 51244751, decimal 10,832,361.
What flights does A549E9 operate?
Mode-S A549E9 has broadcast 1 distinct callsign, including N44SW.