sensors Mode-S transponder

ACF841

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N935AE · EMBRAER ERJ-145 · operated by AMERICAN AIRLINES INC

Hex
ACF841
Octal
53174101
Decimal
11,335,745
Country
US
Tail
N935AE
Type
E145
Photo of N935AE
No current signal · last broadcast 12h ago
Flights observed
14
Distinct callsigns
9
Country
US
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S ACF841.

Country allocation

The ICAO 24-bit address ACF841 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 9 distinct

Callsign Airline Flights Last seen
PDT5927 - 4 2026-04-13
PDT5828 - 3 2026-04-13
PDT6079 Piedmont Airlines 1 2026-04-13
PDT5988 - 1 2026-04-14
PDT5965 - 1 2026-04-12
PDT5867 - 1 2026-04-12
PDT5826 Piedmont Airlines 1 2026-04-13
PDT5818 - 1 2026-04-13
PDT5808 - 1 2026-04-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-14 PDT5988 - Apr 14, 10:15 UTCApr 14, 11:02 UTC47m
2026-04-13 PDT5826 PHL → MSN Apr 13, 22:10 UTCApr 13, 23:00 UTC50m
2026-04-13 PDT5828 - Apr 13, 20:06 UTCApr 13, 20:54 UTC48m
2026-04-13 PDT5828 - Apr 13, 19:45 UTCApr 13, 20:40 UTC55m
2026-04-13 PDT5828 - Apr 13, 18:05 UTCApr 13, 18:55 UTC50m
2026-04-13 PDT5927 - Apr 13, 16:15 UTCApr 13, 16:40 UTC25m
2026-04-13 PDT5927 - Apr 13, 15:50 UTCApr 13, 16:40 UTC50m
2026-04-13 PDT5927 - Apr 13, 15:39 UTCApr 13, 16:47 UTC1h 8m
2026-04-13 PDT5927 - Apr 13, 13:52 UTCApr 13, 14:52 UTC1h 0m
2026-04-13 PDT5808 - Apr 13, 10:30 UTCApr 13, 11:42 UTC1h 12m
2026-04-13 PDT5818 - Apr 13, 03:04 UTCApr 13, 04:22 UTC1h 18m
2026-04-13 PDT6079 CAE → PHL Apr 13, 00:20 UTCApr 13, 00:35 UTC15m
2026-04-12 PDT5965 - Apr 12, 19:05 UTCApr 12, 19:25 UTC20m
2026-04-12 PDT5867 - Apr 12, 17:15 UTCApr 12, 17:30 UTC15m

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 N935AE page for operator, model, and routing details .

Mode-S ACF841 frequently asked

What is Mode-S code ACF841?
ACF841 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N935AE.
Where is Mode-S ACF841 registered?
Mode-S code ACF841 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 ACF841 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACF841, octal 53174101, decimal 11,335,745.
What flights does ACF841 operate?
Mode-S ACF841 has broadcast 9 distinct callsigns, including PDT5927, PDT5828, PDT6079, PDT5988, PDT5965.