Apparatus

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sensors Mode-S transponder

A4BFC1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N405FR · AIRBUS A-320neo · operated by FRONTIER AIRLINES INC.

Hex
A4BFC1
Octal
51137701
Decimal
10,796,993
Country
US
Tail
N405FR
Type
A20N
No current signal · last broadcast Jul 26, 20:50 UTC
Flights observed
511
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 20:50 UTC

Last known position

Most recent position reported by Mode-S A4BFC1.

Country allocation

The ICAO 24-bit address A4BFC1 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
FFT4671 Frontier Airlines 11 2026-04-26
FFT1726 Frontier Airlines 10 2026-06-20
FFT3306 Frontier Airlines 8 2026-06-15
FFT2698 Frontier Airlines 7 2026-04-20
FFT2695 - 7 2026-06-20
FFT4392 Frontier Airlines 6 2026-04-26
FFT3305 Frontier Airlines 6 2026-06-15
FFT3003 - 6 2026-06-19
FFT1165 Frontier Airlines 6 2026-06-20
FFT4725 - 5 2026-06-15
FFT4672 Frontier Airlines 5 2026-04-22
FFT4462 - 5 2026-06-20
FFT2981 - 5 2026-06-21
FFT2697 Frontier Airlines 5 2026-04-21
FFT4771 - 4 2026-07-15
FFT4578 Frontier Airlines 4 2026-04-25
FFT3453 Frontier Airlines 4 2026-05-30
FFT3004 - 4 2026-06-19
FFT2532 Frontier Airlines 4 2026-04-27
FFT2292 - 4 2026-07-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 FFT2452 DEN → MSY Jul 26, 19:25 UTCJul 26, 20:50 UTC1h 25m
2026-07-26 FFT1977 BOS → MCO Jul 26, 14:25 UTCJul 26, 17:00 UTC2h 35m
2026-07-26 FFT1978 MCO → BOS Jul 26, 10:15 UTCJul 26, 12:40 UTC2h 25m
2026-07-25 FFT2530 DTW → MCO Jul 25, 23:35 UTCJul 26, 01:40 UTC2h 5m
2026-07-25 FFT2713 MCO → DTW Jul 25, 20:00 UTCJul 25, 22:10 UTC2h 10m
2026-07-25 FFT2013 TTN → MCO Jul 25, 14:20 UTCJul 25, 16:25 UTC2h 5m
2026-07-25 FFT2742 MCO → TTN Jul 25, 10:10 UTCJul 25, 12:20 UTC2h 10m
2026-07-25 FFT2451 CLT → MCO Jul 25, 00:45 UTCJul 25, 01:55 UTC1h 10m
2026-07-24 FFT3133 PHL → RDU Jul 24, 21:00 UTCJul 24, 22:20 UTC1h 20m
2026-07-24 FFT2432 TPA → CLE Jul 24, 17:15 UTCJul 24, 19:20 UTC2h 5m
2026-07-24 FFT2520 DEN → MCO Jul 24, 06:30 UTCJul 24, 09:50 UTC3h 20m
2026-07-24 FFT4567 STL → DEN Jul 24, 01:40 UTCJul 24, 03:30 UTC1h 50m
2026-07-23 FFT3302 DEN → STL Jul 23, 22:50 UTCJul 24, 00:25 UTC1h 35m
2026-07-23 FFT3565 DTW → DEN Jul 23, 17:40 UTCJul 23, 20:10 UTC2h 30m
2026-07-23 FFT3565 DTW → DEN Jul 23, 17:30 UTCJul 23, 20:04 UTC2h 34m
2026-07-23 FFT3566 DEN → DTW Jul 23, 14:05 UTCJul 23, 16:20 UTC2h 15m
2026-07-23 FFT2107 FSD → DEN Jul 23, 03:50 UTCJul 23, 05:25 UTC1h 35m
2026-07-23 FFT2108 DEN → FSD Jul 23, 00:25 UTCJul 23, 01:30 UTC1h 5m
2026-07-22 FFT2047 - Jul 22, 19:45 UTCJul 22, 21:30 UTC1h 45m
2026-07-22 FFT1816 DEN → AUS Jul 22, 16:30 UTCJul 22, 18:15 UTC1h 45m
2026-07-22 FFT2211 - Jul 22, 11:55 UTCJul 22, 14:45 UTC2h 50m
2026-07-22 FFT4186 DEN → DTW Jul 22, 01:10 UTCJul 22, 03:20 UTC2h 10m
2026-07-21 FFT3406 SEA → DEN Jul 21, 19:55 UTCJul 21, 22:05 UTC2h 10m
2026-07-21 FFT1175 PHL → MCO Jul 21, 15:15 UTCJul 21, 17:40 UTC2h 25m
2026-07-21 FFT3229 IAH → DEN Jul 21, 11:35 UTCJul 21, 13:25 UTC1h 50m
2026-07-21 FFT2996 DEN → IAH Jul 21, 03:25 UTCJul 21, 05:20 UTC1h 55m
2026-07-21 FFT2631 - Jul 21, 00:15 UTCJul 21, 01:45 UTC1h 30m
2026-07-20 FFT2631 DFW → DFW Jul 20, 23:40 UTCJul 20, 23:45 UTC5m
2026-07-20 FFT4070 DEN → DFW Jul 20, 21:05 UTCJul 20, 22:35 UTC1h 30m
2026-07-20 FFT3293 ATL → DEN Jul 20, 16:55 UTCJul 20, 19:20 UTC2h 25m
2026-07-20 FFT3294 DEN → ATL Jul 20, 12:40 UTCJul 20, 15:15 UTC2h 35m
2026-07-20 FFT4561 MSY → DEN Jul 20, 03:55 UTCJul 20, 06:05 UTC2h 10m
2026-07-20 FFT2360 DEN → MSY Jul 20, 00:30 UTCJul 20, 02:50 UTC2h 20m
2026-07-19 FFT3406 SEA → DEN Jul 19, 20:15 UTCJul 19, 22:50 UTC2h 35m
2026-07-19 FFT1175 PHL → MCO Jul 19, 15:15 UTCJul 19, 17:55 UTC2h 40m
2026-07-19 FFT3229 IAH → DEN Jul 19, 11:35 UTCJul 19, 13:25 UTC1h 50m
2026-07-19 FFT2996 DEN → IAH Jul 19, 03:35 UTCJul 19, 05:30 UTC1h 55m
2026-07-19 FFT1927 OKC → DEN Jul 19, 00:50 UTCJul 19, 02:00 UTC1h 10m
2026-07-19 FFT1927 OKC → DEN Jul 19, 00:28 UTCJul 19, 01:59 UTC1h 31m
2026-07-18 FFT1928 DEN → OKC Jul 18, 22:20 UTCJul 18, 23:30 UTC1h 10m
2026-07-18 FFT3375 MCI → DEN Jul 18, 18:55 UTCJul 18, 20:05 UTC1h 10m
2026-07-18 FFT4828 - Jul 18, 16:25 UTCJul 18, 17:35 UTC1h 10m
2026-07-18 FFT1500 - Jul 18, 13:00 UTCJul 18, 14:55 UTC1h 55m
2026-07-18 FFT1500 ONT → DEN Jul 18, 13:13 UTCJul 18, 14:53 UTC1h 40m
2026-07-18 FFT1261 DEN → ONT Jul 18, 04:45 UTCJul 18, 06:30 UTC1h 45m
2026-07-18 FFT2347 - Jul 18, 00:55 UTCJul 18, 03:00 UTC2h 6m
2026-07-17 FFT2348 DEN → IND Jul 17, 21:44 UTCJul 17, 23:50 UTC2h 5m
2026-07-17 FFT2908 ONT → DEN Jul 17, 18:10 UTCJul 17, 20:04 UTC1h 55m
2026-07-17 FFT2908 ONT → DEN Jul 17, 18:02 UTCJul 17, 20:01 UTC1h 59m
2026-07-17 FFT2907 DEN → ONT Jul 17, 15:05 UTCJul 17, 16:49 UTC1h 45m

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 N405FR page for operator, model, and routing details .

Mode-S A4BFC1 frequently asked

What is Mode-S code A4BFC1?
A4BFC1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N405FR.
Where is Mode-S A4BFC1 registered?
Mode-S code A4BFC1 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 A4BFC1 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4BFC1, octal 51137701, decimal 10,796,993.
What flights does A4BFC1 operate?
Mode-S A4BFC1 has broadcast 20 distinct callsigns, including FFT4671, FFT1726, FFT3306, FFT2698, FFT2695.