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
Broadcasting now · callsign FFT2697 · 38,000 ft
Flights observed
15
Distinct callsigns
10
Country
US
Last broadcast
20h ago

Current position

A4BFC1 is currently broadcasting. Map zoomed to live position.

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 10 distinct

Callsign Airline Flights Last seen
FFT4671 - 3 2026-04-13
FFT4392 Frontier Airlines 3 2026-04-13
FFT1719 - 2 2026-04-13
FFT2523 - 1 2026-04-13
FFT2424 - 1 2026-04-12
FFT2423 Frontier Airlines 1 2026-04-12
FFT2141 - 1 2026-04-12
FFT1439 - 1 2026-04-14
FFT1366 - 1 2026-04-13
FFT1191 - 1 2026-04-13

Recent flights last 15

DateFlightRouteTakeoffLandingDuration
2026-04-14 FFT1439 - Apr 14, 05:15 UTCApr 14, 06:15 UTC1h 0m
2026-04-13 FFT1191 - Apr 13, 23:10 UTCApr 13, 23:40 UTC30m
2026-04-13 FFT2523 SLC → PHX Apr 13, 20:35 UTCApr 13, 22:00 UTC1h 25m
2026-04-13 FFT1366 - Apr 13, 18:00 UTCApr 13, 19:25 UTC1h 25m
2026-04-13 FFT1719 - Apr 13, 16:15 UTCApr 13, 16:50 UTC35m
2026-04-13 FFT1719 - Apr 13, 15:45 UTCApr 13, 16:15 UTC30m
2026-04-13 FFT4671 - Apr 13, 12:20 UTCApr 13, 14:10 UTC1h 50m
2026-04-13 FFT4671 - Apr 13, 11:55 UTCApr 13, 14:10 UTC2h 15m
2026-04-13 FFT4671 - Apr 13, 10:10 UTCApr 13, 12:15 UTC2h 5m
2026-04-13 FFT4392 PHX → DTW Apr 13, 04:20 UTCApr 13, 05:05 UTC45m
2026-04-13 FFT4392 PHX → DTW Apr 13, 03:55 UTCApr 13, 05:05 UTC1h 10m
2026-04-13 FFT4392 PHX → DTW Apr 13, 01:20 UTCApr 13, 05:05 UTC3h 45m
2026-04-12 FFT2423 CLE → RSW Apr 12, 23:55 UTCApr 13, 00:10 UTC15m
2026-04-12 FFT2424 - Apr 12, 19:07 UTCApr 12, 20:50 UTC1h 43m
2026-04-12 FFT2141 - Apr 12, 16:28 UTCApr 12, 17:55 UTC1h 27m

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?
Yes. Mode-S A4BFC1 is currently airborne.
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 10 distinct callsigns, including FFT4671, FFT4392, FFT1719, FFT2523, FFT2424.