sensors Mode-S transponder

ACF824

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N9349M · CESSNA 207 Turbo Stationair · operated by DOUBLE R AIR LLC

Hex
ACF824
Octal
53174044
Decimal
11,335,716
Country
US
Tail
N9349M
Type
C207
No current signal · last broadcast 22h ago
Flights observed
5
Distinct callsigns
1
Country
US
Last broadcast
22h ago

Last known position

Most recent position reported by Mode-S ACF824.

Country allocation

The ICAO 24-bit address ACF824 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
N9349M - 5 2026-04-17

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-17 N9349M - Apr 17, 20:25 UTCApr 17, 20:45 UTC20m
2026-04-17 N9349M - Apr 17, 15:20 UTCApr 17, 15:35 UTC15m
2026-04-17 N9349M - Apr 17, 13:45 UTCApr 17, 14:30 UTC45m
2026-04-14 N9349M - Apr 14, 21:20 UTCApr 14, 22:45 UTC1h 25m
2026-04-14 N9349M - Apr 14, 20:05 UTCApr 14, 20:25 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 N9349M page for operator, model, and routing details .

Mode-S ACF824 frequently asked

What is Mode-S code ACF824?
ACF824 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N9349M.
Where is Mode-S ACF824 registered?
Mode-S code ACF824 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 ACF824 broadcasting right now?
No active broadcast right now. Last signal was 22h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACF824, octal 53174044, decimal 11,335,716.
What flights does ACF824 operate?
Mode-S ACF824 has broadcast 1 distinct callsign, including N9349M.