sensors Mode-S transponder

A3EF5E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N35253 · CESSNA 172 Skyhawk · operated by LIU KAIYU

Hex
A3EF5E
Octal
50767536
Decimal
10,743,646
Country
US
Tail
N35253
Type
C172
No current signal · last broadcast 23d ago
Flights observed
34
Distinct callsigns
1
Country
US
Last broadcast
23d ago

Last known position

Most recent position reported by Mode-S A3EF5E.

Country allocation

The ICAO 24-bit address A3EF5E 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
N35253 - 34 2026-05-31

Recent flights last 34

DateFlightRouteTakeoffLandingDuration
2026-05-31 N35253 - May 31, 23:05 UTCMay 31, 23:25 UTC20m
2026-05-31 N35253 - May 31, 14:30 UTCMay 31, 15:35 UTC1h 5m
2026-05-30 N35253 - May 30, 21:40 UTCMay 30, 21:50 UTC10m
2026-05-30 N35253 - May 30, 20:25 UTCMay 30, 20:40 UTC15m
2026-05-30 N35253 - May 30, 17:25 UTCMay 30, 17:35 UTC10m
2026-05-29 N35253 - May 29, 20:30 UTCMay 29, 20:40 UTC10m
2026-05-29 N35253 - May 29, 17:45 UTCMay 29, 18:00 UTC15m
2026-05-28 N35253 - May 28, 20:15 UTCMay 28, 20:25 UTC10m
2026-05-25 N35253 - May 25, 23:49 UTCMay 26, 01:14 UTC1h 25m
2026-05-25 N35253 - May 25, 22:34 UTCMay 25, 22:55 UTC20m
2026-05-22 N35253 - May 22, 19:25 UTCMay 22, 21:30 UTC2h 5m
2026-05-22 N35253 - May 22, 14:15 UTCMay 22, 16:05 UTC1h 50m
2026-05-18 N35253 - May 18, 21:40 UTCMay 18, 22:25 UTC45m
2026-05-18 N35253 - May 18, 20:05 UTCMay 18, 20:50 UTC45m
2026-05-17 N35253 - May 17, 19:45 UTCMay 17, 20:10 UTC25m
2026-05-16 N35253 - May 16, 23:35 UTCMay 16, 23:50 UTC15m
2026-05-15 N35253 - May 15, 00:10 UTCMay 15, 00:20 UTC10m
2026-05-10 N35253 - May 10, 18:20 UTCMay 10, 18:29 UTC10m
2026-05-10 N35253 - May 10, 16:04 UTCMay 10, 16:14 UTC10m
2026-05-08 N35253 - May 8, 19:30 UTCMay 8, 19:50 UTC20m
2026-05-08 N35253 - May 8, 16:55 UTCMay 8, 17:20 UTC25m
2026-05-03 N35253 - May 3, 21:20 UTCMay 3, 21:29 UTC10m
2026-05-03 N35253 - May 3, 16:34 UTCMay 3, 16:50 UTC15m
2026-05-02 N35253 - May 2, 22:00 UTCMay 2, 22:30 UTC30m
2026-04-25 N35253 - Apr 25, 10:10 UTCApr 25, 10:55 UTC45m
2026-04-25 N35253 - Apr 25, 08:35 UTCApr 25, 09:10 UTC35m
2026-04-23 N35253 - Apr 23, 20:30 UTCApr 23, 20:45 UTC15m
2026-04-22 N35253 - Apr 22, 13:50 UTCApr 22, 15:05 UTC1h 15m
2026-04-22 N35253 - Apr 22, 12:25 UTCApr 22, 13:15 UTC50m
2026-04-22 N35253 - Apr 22, 10:55 UTCApr 22, 11:30 UTC35m
2026-04-21 N35253 - Apr 21, 21:15 UTCApr 21, 22:30 UTC1h 15m
2026-04-19 N35253 - Apr 19, 19:35 UTCApr 19, 20:00 UTC25m
2026-04-19 N35253 - Apr 19, 17:15 UTCApr 19, 18:50 UTC1h 35m
2026-04-16 N35253 - Apr 16, 23:20 UTCApr 17, 01:15 UTC1h 55m

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 N35253 page for operator, model, and routing details .

Mode-S A3EF5E frequently asked

What is Mode-S code A3EF5E?
A3EF5E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N35253.
Where is Mode-S A3EF5E registered?
Mode-S code A3EF5E 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 A3EF5E broadcasting right now?
No active broadcast right now. Last signal was 23d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A3EF5E, octal 50767536, decimal 10,743,646.
What flights does A3EF5E operate?
Mode-S A3EF5E has broadcast 1 distinct callsign, including N35253.