sensors Mode-S transponder

A85C01

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N638FR · AIRBUS A-321neo · operated by BANK OF UTAH TRUSTEE

Hex
A85C01
Octal
52056001
Decimal
11,033,601
Country
US
Tail
N638FR
Type
A21N
No current signal · last broadcast 14h ago
Flights observed
11
Distinct callsigns
7
Country
US
Last broadcast
14h ago

Last known position

Most recent position reported by Mode-S A85C01.

Country allocation

The ICAO 24-bit address A85C01 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 7 distinct

Callsign Airline Flights Last seen
FFT4204 - 2 2026-04-14
FFT3107 - 2 2026-04-13
FFT2018 - 2 2026-04-13
FFT1115 Frontier Airlines 2 2026-04-13
FFT4696 - 1 2026-04-13
FFT1080 - 1 2026-04-12
FFT1079 - 1 2026-04-12

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 FFT4204 - Apr 14, 07:10 UTCApr 14, 07:20 UTC10m
2026-04-14 FFT4204 - Apr 14, 05:30 UTCApr 14, 07:10 UTC1h 40m
2026-04-13 FFT4696 LAS → SLC Apr 13, 22:25 UTCApr 13, 23:20 UTC55m
2026-04-13 FFT3107 - Apr 13, 19:50 UTCApr 13, 20:55 UTC1h 5m
2026-04-13 FFT3107 - Apr 13, 17:34 UTCApr 13, 21:00 UTC3h 26m
2026-04-13 FFT2018 - Apr 13, 15:50 UTCApr 13, 16:10 UTC20m
2026-04-13 FFT2018 LAS → STL Apr 13, 13:18 UTCApr 13, 16:20 UTC3h 2m
2026-04-13 FFT1115 ATL → LAS Apr 13, 00:20 UTCApr 13, 03:15 UTC2h 55m
2026-04-12 FFT1115 ATL → LAS Apr 12, 23:55 UTCApr 13, 03:15 UTC3h 20m
2026-04-12 FFT1079 - Apr 12, 20:00 UTCApr 12, 20:15 UTC15m
2026-04-12 FFT1080 - Apr 12, 17:15 UTCApr 12, 18:20 UTC1h 5m

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 N638FR page for operator, model, and routing details .

Mode-S A85C01 frequently asked

What is Mode-S code A85C01?
A85C01 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N638FR.
Where is Mode-S A85C01 registered?
Mode-S code A85C01 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 A85C01 broadcasting right now?
No active broadcast right now. Last signal was 14h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A85C01, octal 52056001, decimal 11,033,601.
What flights does A85C01 operate?
Mode-S A85C01 has broadcast 7 distinct callsigns, including FFT4204, FFT3107, FFT2018, FFT1115, FFT4696.