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sensors Mode-S transponder

A4CEF4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N409KC · operated by KERN COUNTY FIRE DEPARTMENT, KCFD AIR OPERATIONS

Hex
A4CEF4
Octal
51147364
Decimal
10,800,884
Country
US
Tail
N409KC
Type
B412
No current signal · last broadcast Jul 26, 22:05 UTC
Flights observed
105
Distinct callsigns
1
Country
US
Last broadcast
Jul 26, 22:05 UTC

Last known position

Most recent position reported by Mode-S A4CEF4.

Country allocation

The ICAO 24-bit address A4CEF4 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
N409KC - 105 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 N409KC - Jul 26, 21:25 UTCJul 26, 22:05 UTC40m
2026-07-26 N409KC - Jul 26, 18:45 UTCJul 26, 19:35 UTC50m
2026-07-26 N409KC - Jul 26, 00:20 UTCJul 26, 00:35 UTC15m
2026-07-25 N409KC - Jul 25, 23:45 UTCJul 26, 00:15 UTC30m
2026-07-25 N409KC - Jul 25, 19:10 UTCJul 25, 19:40 UTC30m
2026-07-25 N409KC - Jul 25, 00:30 UTCJul 25, 00:45 UTC15m
2026-07-24 N409KC - Jul 24, 15:40 UTCJul 24, 15:55 UTC15m
2026-07-22 N409KC - Jul 22, 23:25 UTCJul 23, 01:45 UTC2h 20m
2026-07-22 N409KC - Jul 22, 16:10 UTCJul 22, 17:05 UTC55m
2026-07-21 N409KC - Jul 21, 19:30 UTCJul 21, 19:45 UTC15m
2026-07-21 N409KC - Jul 21, 16:55 UTCJul 21, 17:10 UTC15m
2026-07-21 N409KC - Jul 21, 04:05 UTCJul 21, 04:20 UTC15m
2026-07-21 N409KC - Jul 21, 02:05 UTCJul 21, 02:15 UTC10m
2026-07-18 N409KC - Jul 18, 22:40 UTCJul 18, 22:55 UTC15m
2026-07-18 N409KC - Jul 18, 20:45 UTCJul 18, 21:00 UTC15m
2026-07-17 N409KC - Jul 17, 19:00 UTCJul 17, 20:55 UTC1h 55m
2026-07-17 N409KC - Jul 17, 02:45 UTCJul 17, 03:39 UTC55m
2026-07-17 N409KC - Jul 17, 01:15 UTCJul 17, 01:29 UTC15m
2026-07-16 N409KC - Jul 16, 23:55 UTCJul 17, 00:40 UTC45m
2026-07-15 N409KC - Jul 15, 16:40 UTCJul 15, 17:40 UTC1h 0m
2026-07-15 N409KC - Jul 15, 16:05 UTCJul 15, 16:20 UTC15m
2026-07-14 N409KC - Jul 14, 15:05 UTCJul 14, 15:50 UTC45m
2026-07-13 N409KC - Jul 13, 23:40 UTCJul 14, 01:45 UTC2h 5m
2026-07-13 N409KC - Jul 13, 15:55 UTCJul 13, 16:20 UTC25m
2026-07-13 N409KC - Jul 13, 02:01 UTCJul 13, 02:15 UTC15m
2026-07-12 N409KC - Jul 12, 23:15 UTCJul 13, 01:20 UTC2h 5m
2026-07-12 N409KC - Jul 12, 19:40 UTCJul 12, 19:55 UTC15m
2026-07-12 N409KC - Jul 12, 02:50 UTCJul 12, 03:05 UTC15m
2026-07-11 N409KC - Jul 11, 23:40 UTCJul 12, 01:15 UTC1h 35m
2026-07-11 N409KC - Jul 11, 19:20 UTCJul 11, 20:40 UTC1h 20m
2026-07-11 N409KC - Jul 11, 18:30 UTCJul 11, 18:50 UTC20m
2026-07-11 N409KC - Jul 11, 16:35 UTCJul 11, 17:50 UTC1h 15m
2026-07-09 N409KC - Jul 9, 14:40 UTCJul 9, 14:55 UTC15m
2026-07-08 N409KC - Jul 8, 23:30 UTCJul 9, 00:20 UTC50m
2026-07-07 N409KC - Jul 7, 16:05 UTCJul 7, 16:25 UTC20m
2026-07-05 N409KC - Jul 5, 21:30 UTCJul 5, 21:40 UTC10m
2026-07-04 N409KC - Jul 4, 20:50 UTCJul 4, 21:20 UTC30m
2026-07-02 N409KC - Jul 2, 23:55 UTCJul 3, 00:30 UTC35m
2026-07-02 N409KC - Jul 2, 04:25 UTCJul 2, 04:45 UTC20m
2026-06-30 N409KC - Jun 30, 20:00 UTCJun 30, 20:30 UTC30m
2026-06-29 N409KC - Jun 29, 22:15 UTCJun 29, 22:30 UTC15m
2026-06-29 N409KC - Jun 29, 18:34 UTCJun 29, 19:09 UTC35m
2026-06-19 N409KC - Jun 19, 20:24 UTCJun 19, 20:59 UTC35m
2026-06-14 N409KC - Jun 14, 16:45 UTCJun 14, 17:15 UTC30m
2026-06-13 N409KC - Jun 13, 22:10 UTCJun 13, 23:00 UTC50m
2026-06-13 N409KC - Jun 13, 18:20 UTCJun 13, 18:30 UTC10m
2026-06-06 N409KC - Jun 6, 18:19 UTCJun 6, 18:29 UTC10m
2026-06-06 N409KC - Jun 6, 17:24 UTCJun 6, 17:34 UTC10m
2026-06-04 N409KC - Jun 4, 21:30 UTCJun 4, 23:05 UTC1h 35m
2026-05-25 N409KC - May 25, 16:30 UTCMay 25, 17:05 UTC35m

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 N409KC page for operator, model, and routing details .

Mode-S A4CEF4 frequently asked

What is Mode-S code A4CEF4?
A4CEF4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N409KC.
Where is Mode-S A4CEF4 registered?
Mode-S code A4CEF4 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 A4CEF4 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4CEF4, octal 51147364, decimal 10,800,884.
What flights does A4CEF4 operate?
Mode-S A4CEF4 has broadcast 1 distinct callsign, including N409KC.