sensors Mode-S transponder

A2F4E3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N29U · CIRRUS SR-22

Hex
A2F4E3
Octal
50572343
Decimal
10,679,523
Country
US
Tail
N29U
Type
SR22
No current signal · last broadcast 2d ago
Flights observed
37
Distinct callsigns
1
Country
US
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S A2F4E3.

Country allocation

The ICAO 24-bit address A2F4E3 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
N29U - 37 2026-07-12

Recent flights last 37

DateFlightRouteTakeoffLandingDuration
2026-07-12 N29U - Jul 12, 21:35 UTCJul 12, 22:35 UTC1h 0m
2026-07-12 N29U - Jul 12, 16:10 UTCJul 12, 17:10 UTC1h 0m
2026-06-28 N29U - Jun 28, 20:25 UTCJun 28, 21:10 UTC45m
2026-06-28 N29U - Jun 28, 17:44 UTCJun 28, 18:29 UTC45m
2026-06-21 N29U - Jun 21, 22:49 UTCJun 22, 00:29 UTC1h 40m
2026-06-21 N29U - Jun 21, 21:44 UTCJun 21, 21:54 UTC10m
2026-06-21 N29U BLM → BTV Jun 21, 14:10 UTCJun 21, 16:25 UTC2h 15m
2026-06-12 N29U - Jun 12, 19:40 UTCJun 12, 21:00 UTC1h 20m
2026-06-12 N29U - Jun 12, 16:00 UTCJun 12, 17:25 UTC1h 25m
2026-06-07 N29U - Jun 7, 20:20 UTCJun 7, 20:50 UTC30m
2026-06-07 N29U - Jun 7, 17:00 UTCJun 7, 17:35 UTC35m
2026-06-05 N29U - Jun 5, 20:15 UTCJun 5, 20:45 UTC30m
2026-06-05 N29U - Jun 5, 17:30 UTCJun 5, 18:15 UTC45m
2026-05-31 N29U - May 31, 23:05 UTCJun 1, 00:00 UTC55m
2026-05-31 N29U - May 31, 18:10 UTCMay 31, 18:55 UTC45m
2026-05-29 N29U - May 29, 19:05 UTCMay 29, 19:40 UTC35m
2026-05-29 N29U - May 29, 15:35 UTCMay 29, 16:10 UTC35m
2026-05-26 N29U - May 26, 22:09 UTCMay 26, 22:54 UTC45m
2026-05-26 N29U - May 26, 15:09 UTCMay 26, 15:54 UTC45m
2026-05-25 N29U - May 25, 20:40 UTCMay 25, 21:04 UTC25m
2026-05-25 N29U - May 25, 19:30 UTCMay 25, 19:50 UTC20m
2026-05-17 N29U - May 17, 22:30 UTCMay 17, 22:50 UTC20m
2026-05-17 N29U - May 17, 19:25 UTCMay 17, 19:45 UTC20m
2026-05-12 N29U - May 12, 16:50 UTCMay 12, 17:10 UTC20m
2026-05-10 N29U - May 10, 18:39 UTCMay 10, 19:15 UTC35m
2026-05-10 N29U BLM → ILG May 10, 16:10 UTCMay 10, 16:50 UTC40m
2026-05-01 N29U - May 1, 20:25 UTCMay 1, 20:45 UTC20m
2026-04-21 N29U - Apr 21, 16:35 UTCApr 21, 16:45 UTC10m
2026-04-16 N29U - Apr 16, 21:14 UTCApr 16, 21:39 UTC25m
2026-04-16 N29U - Apr 16, 19:30 UTCApr 16, 21:10 UTC1h 40m
2026-04-16 N29U - Apr 16, 17:15 UTCApr 16, 17:54 UTC40m
2026-04-16 N29U - Apr 16, 15:50 UTCApr 16, 17:10 UTC1h 20m
2026-04-13 N29U - Apr 13, 19:50 UTCApr 13, 21:15 UTC1h 25m
2026-04-13 N29U - Apr 13, 17:45 UTCApr 13, 20:10 UTC2h 25m
2026-04-13 N29U - Apr 13, 16:15 UTCApr 13, 16:55 UTC40m
2026-04-13 N29U - Apr 13, 15:50 UTCApr 13, 16:55 UTC1h 5m
2026-04-13 N29U - Apr 13, 14:30 UTCApr 13, 16:15 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 N29U page for operator, model, and routing details .

Mode-S A2F4E3 frequently asked

What is Mode-S code A2F4E3?
A2F4E3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N29U.
Where is Mode-S A2F4E3 registered?
Mode-S code A2F4E3 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 A2F4E3 broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2F4E3, octal 50572343, decimal 10,679,523.
What flights does A2F4E3 operate?
Mode-S A2F4E3 has broadcast 1 distinct callsign, including N29U.