sensors Mode-S transponder

A3E99C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N351ME · CESSNA 172 Skyhawk · operated by PS N351ME LLC

Hex
A3E99C
Octal
50764634
Decimal
10,742,172
Country
US
Tail
N351ME
Type
C172
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A3E99C.

Country allocation

The ICAO 24-bit address A3E99C 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
N351ME - 7 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 N351ME GRB → GRB Apr 13, 21:45 UTCApr 13, 22:20 UTC35m
2026-04-13 N351ME - Apr 13, 18:35 UTCApr 13, 19:30 UTC55m
2026-04-13 N351ME - Apr 13, 16:15 UTCApr 13, 17:15 UTC1h 0m
2026-04-13 N351ME - Apr 13, 16:10 UTCApr 13, 17:15 UTC1h 5m
2026-04-13 N351ME GRB → GRB Apr 13, 14:25 UTCApr 13, 15:20 UTC55m
2026-04-13 N351ME - Apr 13, 13:25 UTCApr 13, 13:45 UTC20m
2026-04-13 N351ME - Apr 13, 12:20 UTCApr 13, 12:40 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 N351ME page for operator, model, and routing details .

Mode-S A3E99C frequently asked

What is Mode-S code A3E99C?
A3E99C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N351ME.
Where is Mode-S A3E99C registered?
Mode-S code A3E99C 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 A3E99C broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A3E99C, octal 50764634, decimal 10,742,172.
What flights does A3E99C operate?
Mode-S A3E99C has broadcast 1 distinct callsign, including N351ME.