sensors Mode-S transponder

A9CE54

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N73066 · CESSNA 120

Hex
A9CE54
Octal
52347124
Decimal
11,128,404
Country
US
Tail
N73066
Type
C120
No current signal · last broadcast Jul 23, 22:10 UTC
Flights observed
11
Distinct callsigns
1
Country
US
Last broadcast
Jul 23, 22:10 UTC

Last known position

Most recent position reported by Mode-S A9CE54.

Country allocation

The ICAO 24-bit address A9CE54 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
N73066 - 11 2026-07-23

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-07-23 N73066 - Jul 23, 20:00 UTCJul 23, 22:10 UTC2h 10m
2026-07-23 N73066 - Jul 23, 19:00 UTCJul 23, 19:25 UTC25m
2026-07-23 N73066 - Jul 23, 14:55 UTCJul 23, 17:45 UTC2h 50m
2026-07-19 N73066 - Jul 19, 19:20 UTCJul 19, 20:55 UTC1h 35m
2026-07-18 N73066 - Jul 18, 20:45 UTCJul 18, 21:15 UTC30m
2026-07-18 N73066 - Jul 18, 15:25 UTCJul 18, 16:00 UTC35m
2026-07-15 N73066 - Jul 15, 19:45 UTCJul 15, 20:10 UTC25m
2026-05-31 N73066 - May 31, 18:00 UTCMay 31, 18:10 UTC10m
2026-05-24 N73066 - May 24, 21:00 UTCMay 24, 21:10 UTC10m
2026-05-24 N73066 - May 24, 19:40 UTCMay 24, 20:05 UTC25m
2026-05-22 N73066 - May 22, 20:35 UTCMay 22, 20:55 UTC20m

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 N73066 page for operator, model, and routing details .

Mode-S A9CE54 frequently asked

What is Mode-S code A9CE54?
A9CE54 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N73066.
Where is Mode-S A9CE54 registered?
Mode-S code A9CE54 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 A9CE54 broadcasting right now?
No active broadcast right now. Last signal was Jul 23, 22:10 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9CE54, octal 52347124, decimal 11,128,404.
What flights does A9CE54 operate?
Mode-S A9CE54 has broadcast 1 distinct callsign, including N73066.