sensors Mode-S transponder

A6FEF5

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N55VH · operated by COMBINED AIRCRAFT OWNERSHIP LLC

Hex
A6FEF5
Octal
51577365
Decimal
10,944,245
Country
US
Tail
N55VH
Type
C525
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A6FEF5.

Country allocation

The ICAO 24-bit address A6FEF5 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
N55VH - 5 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 N55VH - Apr 13, 20:25 UTCApr 13, 21:10 UTC45m
2026-04-13 N55VH - Apr 13, 19:45 UTCApr 13, 19:55 UTC10m
2026-04-13 N55VH - Apr 13, 18:15 UTCApr 13, 19:55 UTC1h 40m
2026-04-13 N55VH - Apr 13, 16:15 UTCApr 13, 17:05 UTC50m
2026-04-13 N55VH - Apr 13, 15:55 UTCApr 13, 16:15 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 N55VH page for operator, model, and routing details .

Mode-S A6FEF5 frequently asked

What is Mode-S code A6FEF5?
A6FEF5 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N55VH.
Where is Mode-S A6FEF5 registered?
Mode-S code A6FEF5 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 A6FEF5 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 A6FEF5, octal 51577365, decimal 10,944,245.
What flights does A6FEF5 operate?
Mode-S A6FEF5 has broadcast 1 distinct callsign, including N55VH.