sensors Mode-S transponder

ACF8F3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N935HH · EMBRAER EMB-550 Praetor 600

Hex
ACF8F3
Octal
53174363
Decimal
11,335,923
Country
US
Tail
N935HH
Type
E550
No current signal · last broadcast 4h ago
Flights observed
10
Distinct callsigns
1
Country
US
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S ACF8F3.

Country allocation

The ICAO 24-bit address ACF8F3 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
EJM935 - 10 2026-04-29

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-29 EJM935 - Apr 29, 00:59 UTCApr 29, 01:40 UTC40m
2026-04-28 EJM935 - Apr 28, 22:10 UTCApr 28, 22:40 UTC30m
2026-04-28 EJM935 - Apr 28, 19:05 UTCApr 28, 20:55 UTC1h 50m
2026-04-28 EJM935 - Apr 28, 10:30 UTCApr 28, 12:25 UTC1h 55m
2026-04-27 EJM935 - Apr 27, 16:35 UTCApr 27, 17:10 UTC35m
2026-04-27 EJM935 - Apr 27, 15:05 UTCApr 27, 15:40 UTC35m
2026-04-19 EJM935 - Apr 19, 19:50 UTCApr 19, 20:30 UTC40m
2026-04-19 EJM935 - Apr 19, 18:15 UTCApr 19, 18:55 UTC40m
2026-04-16 EJM935 - Apr 16, 19:15 UTCApr 16, 19:50 UTC35m
2026-04-16 EJM935 - Apr 16, 18:20 UTCApr 16, 19:10 UTC50m

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 N935HH page for operator, model, and routing details .

Mode-S ACF8F3 frequently asked

What is Mode-S code ACF8F3?
ACF8F3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N935HH.
Where is Mode-S ACF8F3 registered?
Mode-S code ACF8F3 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 ACF8F3 broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACF8F3, octal 53174363, decimal 11,335,923.
What flights does ACF8F3 operate?
Mode-S ACF8F3 has broadcast 1 distinct callsign, including EJM935.