sensors Mode-S transponder

A552FD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N442KS · CESSNA 172 Skyhawk · operated by CHRISTIANSEN AVIATION LLC

Hex
A552FD
Octal
51251375
Decimal
10,834,685
Country
US
Tail
N442KS
Type
C172
Broadcasting now · callsign N442KS · 2,900 ft
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Current position

A552FD is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A552FD 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
N442KS - 6 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 N442KS - Apr 13, 20:55 UTCApr 13, 21:40 UTC45m
2026-04-13 N442KS - Apr 13, 19:15 UTCApr 13, 19:30 UTC15m
2026-04-13 N442KS - Apr 13, 17:50 UTCApr 13, 18:35 UTC45m
2026-04-13 N442KS - Apr 13, 15:50 UTCApr 13, 16:20 UTC30m
2026-04-13 N442KS - Apr 13, 14:50 UTCApr 13, 16:15 UTC1h 25m
2026-04-12 N442KS - Apr 12, 18:20 UTCApr 12, 18:55 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 N442KS page for operator, model, and routing details .

Mode-S A552FD frequently asked

What is Mode-S code A552FD?
A552FD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N442KS.
Where is Mode-S A552FD registered?
Mode-S code A552FD 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 A552FD broadcasting right now?
Yes. Mode-S A552FD is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A552FD, octal 51251375, decimal 10,834,685.
What flights does A552FD operate?
Mode-S A552FD has broadcast 1 distinct callsign, including N442KS.