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sensors Mode-S transponder

A6F1A4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N54678 · CESSNA 172 Skyhawk · operated by AERO ASSOCIATION OF CALTECH INC

Hex
A6F1A4
Octal
51570644
Decimal
10,940,836
Country
US
Tail
N54678
Type
C172
No current signal · last broadcast 23h ago
Flights observed
142
Distinct callsigns
1
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A6F1A4.

Country allocation

The ICAO 24-bit address A6F1A4 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
N54678 - 142 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 N54678 EMT → EMT Jul 13, 16:55 UTCJul 13, 17:30 UTC35m
2026-07-11 N54678 - Jul 11, 23:30 UTCJul 12, 00:45 UTC1h 15m
2026-07-11 N54678 SMX → EMT Jul 11, 00:50 UTCJul 11, 02:05 UTC1h 15m
2026-07-10 N54678 - Jul 10, 23:40 UTCJul 11, 00:45 UTC1h 5m
2026-07-10 N54678 - Jul 10, 21:40 UTCJul 10, 23:00 UTC1h 20m
2026-07-09 N54678 - Jul 9, 22:30 UTCJul 9, 23:45 UTC1h 15m
2026-07-08 N54678 - Jul 8, 22:55 UTCJul 9, 00:15 UTC1h 20m
2026-07-08 N54678 - Jul 8, 20:40 UTCJul 8, 21:45 UTC1h 5m
2026-07-08 N54678 - Jul 8, 02:00 UTCJul 8, 02:40 UTC40m
2026-07-07 N54678 EMT → EMT Jul 7, 22:20 UTCJul 7, 23:50 UTC1h 30m
2026-07-06 N54678 - Jul 6, 23:35 UTCJul 7, 00:40 UTC1h 5m
2026-07-06 N54678 - Jul 6, 17:05 UTCJul 6, 17:55 UTC50m
2026-07-05 N54678 CCB → EMT Jul 5, 18:05 UTCJul 5, 19:15 UTC1h 10m
2026-07-05 N54678 EMT → CCB Jul 5, 16:25 UTCJul 5, 17:20 UTC55m
2026-07-05 N54678 - Jul 5, 03:50 UTCJul 5, 04:55 UTC1h 5m
2026-07-03 N54678 - Jul 3, 23:35 UTCJul 4, 00:00 UTC25m
2026-07-03 N54678 - Jul 3, 22:25 UTCJul 3, 22:45 UTC20m
2026-07-03 N54678 - Jul 3, 20:25 UTCJul 3, 21:30 UTC1h 5m
2026-07-01 N54678 - Jul 1, 22:00 UTCJul 1, 23:15 UTC1h 15m
2026-07-01 N54678 - Jul 1, 21:00 UTCJul 1, 21:15 UTC15m
2026-07-01 N54678 - Jul 1, 20:05 UTCJul 1, 20:30 UTC25m
2026-07-01 N54678 - Jul 1, 05:25 UTCJul 1, 06:45 UTC1h 20m
2026-07-01 N54678 - Jul 1, 01:50 UTCJul 1, 03:25 UTC1h 35m
2026-06-30 N54678 - Jun 30, 22:45 UTCJun 30, 22:55 UTC10m
2026-06-29 N54678 - Jun 29, 23:54 UTCJun 30, 00:09 UTC15m
2026-06-29 N54678 - Jun 29, 21:50 UTCJun 29, 22:44 UTC55m
2026-06-29 N54678 EMT → CCB Jun 29, 00:34 UTCJun 29, 00:49 UTC15m
2026-06-27 N54678 - Jun 27, 21:44 UTCJun 28, 00:35 UTC2h 50m
2026-06-27 N54678 - Jun 27, 19:00 UTCJun 27, 20:19 UTC1h 20m
2026-06-26 N54678 - Jun 26, 23:55 UTCJun 27, 01:15 UTC1h 20m
2026-06-26 N54678 - Jun 26, 20:34 UTCJun 26, 21:50 UTC1h 15m
2026-06-26 N54678 - Jun 26, 04:59 UTCJun 26, 05:39 UTC40m
2026-06-26 N54678 - Jun 26, 03:24 UTCJun 26, 04:00 UTC35m
2026-06-25 N54678 - Jun 25, 19:20 UTCJun 25, 19:34 UTC15m
2026-06-24 N54678 EMT → EMT Jun 24, 21:09 UTCJun 24, 22:04 UTC55m
2026-06-23 N54678 - Jun 23, 19:34 UTCJun 23, 20:54 UTC1h 20m
2026-06-23 N54678 EMT → EMT Jun 23, 04:00 UTCJun 23, 05:34 UTC1h 35m
2026-06-23 N54678 EMT → EMT Jun 23, 01:10 UTCJun 23, 02:29 UTC1h 20m
2026-06-22 N54678 EMT → EMT Jun 22, 20:39 UTCJun 22, 21:35 UTC55m
2026-06-22 N54678 EMT → EMT Jun 22, 16:34 UTCJun 22, 18:00 UTC1h 25m
2026-06-19 N54678 - Jun 19, 17:04 UTCJun 19, 18:20 UTC1h 15m
2026-06-19 N54678 - Jun 19, 15:19 UTCJun 19, 16:34 UTC1h 15m
2026-06-18 N54678 - Jun 18, 21:25 UTCJun 18, 22:15 UTC50m
2026-06-17 N54678 - Jun 17, 20:40 UTCJun 17, 22:20 UTC1h 40m
2026-06-17 N54678 - Jun 17, 01:00 UTCJun 17, 02:05 UTC1h 5m
2026-06-16 N54678 - Jun 16, 21:35 UTCJun 16, 22:55 UTC1h 20m
2026-06-16 N54678 - Jun 16, 18:15 UTCJun 16, 19:19 UTC1h 5m
2026-06-16 N54678 EMT → SBA Jun 16, 17:00 UTCJun 16, 17:59 UTC1h 0m
2026-06-15 N54678 - Jun 15, 20:25 UTCJun 15, 21:35 UTC1h 10m
2026-06-15 N54678 EMT → EMT Jun 15, 16:40 UTCJun 15, 17:40 UTC1h 0m

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 N54678 page for operator, model, and routing details .

Mode-S A6F1A4 frequently asked

What is Mode-S code A6F1A4?
A6F1A4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N54678.
Where is Mode-S A6F1A4 registered?
Mode-S code A6F1A4 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 A6F1A4 broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A6F1A4, octal 51570644, decimal 10,940,836.
What flights does A6F1A4 operate?
Mode-S A6F1A4 has broadcast 1 distinct callsign, including N54678.