sensors Mode-S transponder

A6E441

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N543ND · CESSNA 172 Skyhawk · operated by N543ND LLC

Hex
A6E441
Octal
51562101
Decimal
10,937,409
Country
US
Tail
N543ND
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 A6E441.

Country allocation

The ICAO 24-bit address A6E441 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
AVL121 - 7 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 AVL121 - Apr 13, 22:50 UTCApr 13, 23:40 UTC50m
2026-04-13 AVL121 - Apr 13, 16:15 UTCApr 13, 17:40 UTC1h 25m
2026-04-13 AVL121 - Apr 13, 15:50 UTCApr 13, 16:15 UTC25m
2026-04-13 AVL121 - Apr 13, 12:55 UTCApr 13, 14:30 UTC1h 35m
2026-04-13 AVL121 - Apr 13, 11:55 UTCApr 13, 12:20 UTC25m
2026-04-13 AVL121 - Apr 13, 11:40 UTCApr 13, 12:15 UTC35m
2026-04-12 AVL121 - Apr 12, 17:55 UTCApr 12, 18:30 UTC35m

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 N543ND page for operator, model, and routing details .

Mode-S A6E441 frequently asked

What is Mode-S code A6E441?
A6E441 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N543ND.
Where is Mode-S A6E441 registered?
Mode-S code A6E441 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 A6E441 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 A6E441, octal 51562101, decimal 10,937,409.
What flights does A6E441 operate?
Mode-S A6E441 has broadcast 1 distinct callsign, including AVL121.