sensors Mode-S transponder

A25558

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N25CA · PIPER PA-32RT-300/300T · operated by WHITE DOG AVIATION LLC

Hex
A25558
Octal
50452530
Decimal
10,638,680
Country
US
Tail
N25CA
Type
P32T
No current signal · last broadcast Jun 18, 19:55 UTC
Flights observed
10
Distinct callsigns
1
Country
US
Last broadcast
Jun 18, 19:55 UTC

Last known position

Most recent position reported by Mode-S A25558.

Country allocation

The ICAO 24-bit address A25558 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
N25CA - 10 2026-06-18

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-06-18 N25CA - Jun 18, 18:45 UTCJun 18, 19:55 UTC1h 10m
2026-06-12 N25CA - Jun 12, 18:20 UTCJun 12, 18:55 UTC35m
2026-06-12 N25CA - Jun 12, 16:45 UTCJun 12, 18:15 UTC1h 30m
2026-06-07 N25CA PAO → PAO Jun 7, 17:30 UTCJun 7, 19:30 UTC2h 0m
2026-05-21 N25CA - May 21, 20:40 UTCMay 21, 21:05 UTC25m
2026-05-21 N25CA - May 21, 18:15 UTCMay 21, 18:50 UTC35m
2026-05-11 N25CA - May 11, 19:40 UTCMay 11, 20:30 UTC50m
2026-05-01 N25CA - May 1, 22:10 UTCMay 1, 22:30 UTC20m
2026-05-01 N25CA - May 1, 20:10 UTCMay 1, 20:30 UTC20m
2026-04-19 N25CA PAO → PAO Apr 19, 05:20 UTCApr 19, 05:25 UTC5m

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 N25CA page for operator, model, and routing details .

Mode-S A25558 frequently asked

What is Mode-S code A25558?
A25558 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N25CA.
Where is Mode-S A25558 registered?
Mode-S code A25558 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 A25558 broadcasting right now?
No active broadcast right now. Last signal was Jun 18, 19:55 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A25558, octal 50452530, decimal 10,638,680.
What flights does A25558 operate?
Mode-S A25558 has broadcast 1 distinct callsign, including N25CA.