sensors Mode-S transponder

ACF39D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N9333P · PIPER PA-24 Comanche · operated by SKY WEST AVIATION INC TRUSTEE

Hex
ACF39D
Octal
53171635
Decimal
11,334,557
Country
US
Tail
N9333P
Type
PA24
No current signal · last broadcast 1d ago
Flights observed
2
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S ACF39D.

Country allocation

The ICAO 24-bit address ACF39D 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
N9333P - 2 2026-04-13

Recent flights last 2

DateFlightRouteTakeoffLandingDuration
2026-04-13 N9333P - Apr 13, 21:15 UTCApr 13, 21:35 UTC20m
2026-04-13 N9333P - Apr 13, 13:05 UTCApr 13, 13:30 UTC25m

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 N9333P page for operator, model, and routing details .

Mode-S ACF39D frequently asked

What is Mode-S code ACF39D?
ACF39D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N9333P.
Where is Mode-S ACF39D registered?
Mode-S code ACF39D 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 ACF39D 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 ACF39D, octal 53171635, decimal 11,334,557.
What flights does ACF39D operate?
Mode-S ACF39D has broadcast 1 distinct callsign, including N9333P.