sensors Mode-S transponder

A6DCD4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N541NE

Hex
A6DCD4
Octal
51556324
Decimal
10,935,508
Country
US
Tail
N541NE
No current signal · last broadcast 5d ago
Flights observed
13
Distinct callsigns
1
Country
US
Last broadcast
5d ago

Last known position

Most recent position reported by Mode-S A6DCD4.

Country allocation

The ICAO 24-bit address A6DCD4 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
N541NE - 13 2026-07-25

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-07-25 N541NE - Jul 25, 17:40 UTCJul 25, 18:35 UTC55m
2026-07-24 N541NE - Jul 24, 13:10 UTCJul 24, 13:45 UTC35m
2026-07-21 N541NE - Jul 21, 11:40 UTCJul 21, 12:20 UTC40m
2026-07-20 N541NE - Jul 20, 22:55 UTCJul 20, 23:35 UTC40m
2026-07-19 N541NE - Jul 19, 23:25 UTCJul 19, 23:40 UTC15m
2026-07-19 N541NE - Jul 19, 22:35 UTCJul 19, 23:20 UTC45m
2026-07-16 N541NE - Jul 16, 00:20 UTCJul 16, 00:30 UTC10m
2026-07-12 N541NE - Jul 12, 18:30 UTCJul 12, 19:30 UTC1h 0m
2026-07-11 N541NE - Jul 11, 22:15 UTCJul 11, 22:45 UTC30m
2026-06-28 N541NE - Jun 28, 22:39 UTCJun 28, 23:09 UTC30m
2026-06-25 N541NE - Jun 25, 23:55 UTCJun 26, 00:10 UTC15m
2026-06-24 N541NE - Jun 24, 12:09 UTCJun 24, 12:20 UTC10m
2026-06-22 N541NE - Jun 22, 12:34 UTCJun 22, 12:44 UTC10m

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 N541NE page for operator, model, and routing details .

Mode-S A6DCD4 frequently asked

What is Mode-S code A6DCD4?
A6DCD4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N541NE.
Where is Mode-S A6DCD4 registered?
Mode-S code A6DCD4 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 A6DCD4 broadcasting right now?
No active broadcast right now. Last signal was 5d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A6DCD4, octal 51556324, decimal 10,935,508.
What flights does A6DCD4 operate?
Mode-S A6DCD4 has broadcast 1 distinct callsign, including N541NE.