Apparatus

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sensors Mode-S transponder

A4CE9D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N409FR · AIRBUS A-320neo · operated by FRONTIER AIRLINES INC.

Hex
A4CE9D
Octal
51147235
Decimal
10,800,797
Country
US
Tail
N409FR
Type
A20N
No current signal · last broadcast 2h ago
Flights observed
253
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A4CE9D.

Country allocation

The ICAO 24-bit address A4CE9D 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 20 distinct

Callsign Airline Flights Last seen
FFT4420 Frontier Airlines 14 2026-05-29
FFT4419 Frontier Airlines 14 2026-05-29
FFT241 Frontier Airlines 12 2026-05-29
FFT1165 Frontier Airlines 10 2026-05-05
FFT240 - 9 2026-05-30
FFT4916 Frontier Airlines 8 2026-05-10
FFT4915 Frontier Airlines 8 2026-05-10
FFT1726 Frontier Airlines 8 2026-05-19
FFT1016 Frontier Airlines 7 2026-04-21
FFT2695 Frontier Airlines 6 2026-05-19
FFT3054 Frontier Airlines 5 2026-04-26
FFT3053 Frontier Airlines 5 2026-04-26
FFT4726 Frontier Airlines 4 2026-05-18
FFT1824 Frontier Airlines 4 2026-05-21
FFT4206 Frontier Airlines 3 2026-04-29
FFT3043 Frontier Airlines 3 2026-04-13
FFT3003 Frontier Airlines 3 2026-05-18
FFT2981 Frontier Airlines 3 2026-05-20
FFT2792 - 3 2026-04-13
FFT2742 Frontier Airlines 3 2026-05-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 FFT240 - May 30, 01:55 UTCMay 30, 02:10 UTC15m
2026-05-29 FFT241 SJU → PUJ May 29, 23:35 UTCMay 29, 23:50 UTC15m
2026-05-29 FFT4420 BDL → SJU May 29, 21:15 UTCMay 29, 21:40 UTC25m
2026-05-29 FFT4420 BDL → SJU May 29, 18:25 UTCMay 29, 18:55 UTC30m
2026-05-29 FFT4419 SJU → BDL May 29, 15:35 UTCMay 29, 16:55 UTC1h 20m
2026-05-29 FFT4419 SJU → BDL May 29, 12:50 UTCMay 29, 13:05 UTC15m
2026-05-29 FFT240 - May 29, 02:55 UTCMay 29, 03:05 UTC10m
2026-05-29 FFT241 SJU → PUJ May 29, 01:20 UTCMay 29, 01:30 UTC10m
2026-05-28 FFT4420 BDL → SJU May 28, 18:50 UTCMay 28, 22:05 UTC3h 15m
2026-05-28 FFT4419 SJU → BDL May 28, 12:45 UTCMay 28, 16:25 UTC3h 40m
2026-05-28 FFT4419 SJU → BDL May 28, 12:46 UTCMay 28, 16:20 UTC3h 34m
2026-05-28 FFT240 - May 28, 01:50 UTCMay 28, 02:00 UTC10m
2026-05-27 FFT241 SJU → PUJ May 27, 23:40 UTCMay 27, 23:55 UTC15m
2026-05-27 FFT4420 BDL → SJU May 27, 18:10 UTCMay 27, 22:15 UTC4h 5m
2026-05-27 FFT4419 SJU → BDL May 27, 12:40 UTCMay 27, 16:25 UTC3h 45m
2026-05-27 FFT240 - May 27, 02:04 UTCMay 27, 02:19 UTC15m
2026-05-26 FFT241 SJU → PUJ May 26, 23:19 UTCMay 26, 23:35 UTC15m
2026-05-26 FFT241 SJU → PUJ May 26, 23:28 UTCMay 26, 23:49 UTC21m
2026-05-26 FFT4420 BDL → SJU May 26, 17:55 UTCMay 26, 21:25 UTC3h 30m
2026-05-26 FFT4419 SJU → BDL May 26, 12:35 UTCMay 26, 16:10 UTC3h 35m
2026-05-26 FFT240 - May 26, 02:19 UTCMay 26, 02:35 UTC15m
2026-05-25 FFT241 SJU → PUJ May 25, 23:30 UTCMay 25, 23:45 UTC15m
2026-05-25 FFT241 SJU → PUJ May 25, 23:28 UTCMay 26, 00:02 UTC34m
2026-05-25 FFT4420 BDL → SJU May 25, 18:05 UTCMay 25, 21:19 UTC3h 14m
2026-05-25 FFT4419 SJU → BDL May 25, 12:45 UTCMay 25, 16:20 UTC3h 35m
2026-05-25 FFT240 - May 25, 02:05 UTCMay 25, 02:15 UTC10m
2026-05-24 FFT241 SJU → PUJ May 24, 23:30 UTCMay 24, 23:46 UTC16m
2026-05-24 FFT4420 BDL → SJU May 24, 21:00 UTCMay 24, 21:30 UTC30m
2026-05-24 FFT4420 BDL → SJU May 24, 18:00 UTCMay 24, 18:40 UTC40m
2026-05-24 FFT4419 SJU → BDL May 24, 12:40 UTCMay 24, 16:10 UTC3h 30m
2026-05-24 FFT240 - May 24, 01:50 UTCMay 24, 02:00 UTC10m
2026-05-23 FFT241 SJU → PUJ May 23, 23:15 UTCMay 23, 23:25 UTC10m
2026-05-23 FFT241 SJU → PUJ May 23, 23:28 UTCMay 23, 23:44 UTC16m
2026-05-23 FFT4420 BDL → SJU May 23, 17:55 UTCMay 23, 21:20 UTC3h 26m
2026-05-23 FFT4419 SJU → BDL May 23, 12:40 UTCMay 23, 16:10 UTC3h 30m
2026-05-23 FFT240 - May 23, 02:35 UTCMay 23, 02:45 UTC10m
2026-05-22 FFT241 SJU → PUJ May 22, 23:35 UTCMay 22, 23:45 UTC10m
2026-05-22 FFT4420 BDL → SJU May 22, 20:55 UTCMay 22, 21:15 UTC20m
2026-05-22 FFT4420 BDL → SJU May 22, 17:55 UTCMay 22, 19:15 UTC1h 20m
2026-05-22 FFT4419 SJU → BDL May 22, 12:40 UTCMay 22, 13:00 UTC20m
2026-05-22 FFT4419 SJU → BDL May 22, 12:46 UTCMay 22, 16:21 UTC3h 35m
2026-05-22 FFT240 - May 22, 02:00 UTCMay 22, 02:10 UTC10m
2026-05-22 FFT241 SJU → PUJ May 22, 00:00 UTCMay 22, 00:15 UTC15m
2026-05-21 FFT1824 MCO → SJU May 21, 20:40 UTCMay 21, 21:00 UTC20m
2026-05-21 FFT1824 MCO → SJU May 21, 18:35 UTCMay 21, 19:15 UTC40m
2026-05-21 FFT2013 TTN → MCO May 21, 15:00 UTCMay 21, 17:10 UTC2h 10m
2026-05-21 FFT2742 MCO → TTN May 21, 11:20 UTCMay 21, 13:30 UTC2h 10m
2026-05-21 FFT1750 CVG → MCO May 21, 01:45 UTCMay 21, 03:20 UTC1h 35m
2026-05-20 FFT1713 MCO → CVG May 20, 15:00 UTCMay 20, 16:55 UTC1h 55m
2026-05-20 FFT2981 SJU → MCO May 20, 10:10 UTCMay 20, 12:50 UTC2h 40m

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 N409FR page for operator, model, and routing details .

Mode-S A4CE9D frequently asked

What is Mode-S code A4CE9D?
A4CE9D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N409FR.
Where is Mode-S A4CE9D registered?
Mode-S code A4CE9D 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 A4CE9D broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4CE9D, octal 51147235, decimal 10,800,797.
What flights does A4CE9D operate?
Mode-S A4CE9D has broadcast 20 distinct callsigns, including FFT4420, FFT4419, FFT241, FFT1165, FFT240.