sensors Mode-S transponder

A1F639

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N2252G · CESSNA 182 Skylane · operated by RUTTER ERIC R

Hex
A1F639
Octal
50373071
Decimal
10,614,329
Country
US
Tail
N2252G
Type
C182
No current signal · last broadcast Jul 13, 21:00 UTC
Flights observed
14
Distinct callsigns
1
Country
US
Last broadcast
Jul 13, 21:00 UTC

Last known position

Most recent position reported by Mode-S A1F639.

Country allocation

The ICAO 24-bit address A1F639 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
N2252G - 14 2026-07-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-07-13 N2252G - Jul 13, 20:40 UTCJul 13, 21:00 UTC20m
2026-07-11 N2252G - Jul 11, 01:05 UTCJul 11, 01:25 UTC20m
2026-07-05 N2252G - Jul 5, 17:45 UTCJul 5, 18:00 UTC15m
2026-07-02 N2252G - Jul 2, 17:55 UTCJul 2, 18:15 UTC20m
2026-06-28 N2252G - Jun 28, 19:34 UTCJun 28, 19:59 UTC25m
2026-06-27 N2252G - Jun 27, 19:55 UTCJun 27, 20:29 UTC35m
2026-06-20 N2252G - Jun 20, 20:14 UTCJun 20, 20:29 UTC15m
2026-06-17 N2252G - Jun 17, 18:30 UTCJun 17, 18:50 UTC20m
2026-05-31 N2252G - May 31, 22:20 UTCMay 31, 22:40 UTC20m
2026-05-30 N2252G - May 30, 22:40 UTCMay 30, 23:00 UTC20m
2026-05-30 N2252G - May 30, 21:40 UTCMay 30, 21:55 UTC15m
2026-05-30 N2252G - May 30, 19:55 UTCMay 30, 20:15 UTC20m
2026-05-25 N2252G - May 25, 02:25 UTCMay 25, 02:40 UTC15m
2026-05-23 N2252G - May 23, 18:35 UTCMay 23, 18:55 UTC20m

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 N2252G page for operator, model, and routing details .

Mode-S A1F639 frequently asked

What is Mode-S code A1F639?
A1F639 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N2252G.
Where is Mode-S A1F639 registered?
Mode-S code A1F639 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 A1F639 broadcasting right now?
No active broadcast right now. Last signal was Jul 13, 21:00 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1F639, octal 50373071, decimal 10,614,329.
What flights does A1F639 operate?
Mode-S A1F639 has broadcast 1 distinct callsign, including N2252G.