sensors Mode-S transponder

AD2D51

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N94800 · CESSNA 182 Skylane · operated by CIVIL AIR PATROL INC

Hex
AD2D51
Octal
53226521
Decimal
11,349,329
Country
US
Tail
N94800
Type
C182
No current signal · last broadcast 26d ago
Flights observed
9
Distinct callsigns
2
Country
US
Last broadcast
26d ago

Last known position

Most recent position reported by Mode-S AD2D51.

Country allocation

The ICAO 24-bit address AD2D51 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 2 distinct

Callsign Airline Flights Last seen
CAP401 - 6 2026-04-29
N94800 - 3 2026-05-08

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-05-08 N94800 - May 8, 17:00 UTCMay 8, 17:15 UTC15m
2026-05-03 N94800 - May 3, 21:54 UTCMay 3, 22:20 UTC25m
2026-05-02 N94800 - May 2, 00:05 UTCMay 2, 00:15 UTC10m
2026-04-29 CAP401 - Apr 29, 16:05 UTCApr 29, 16:15 UTC10m
2026-04-27 CAP401 - Apr 27, 22:00 UTCApr 27, 22:10 UTC10m
2026-04-27 CAP401 - Apr 27, 21:10 UTCApr 27, 21:35 UTC25m
2026-04-26 CAP401 - Apr 26, 22:45 UTCApr 26, 23:00 UTC15m
2026-04-23 CAP401 - Apr 23, 19:00 UTCApr 23, 19:35 UTC35m
2026-04-23 CAP401 - Apr 23, 17:50 UTCApr 23, 18:15 UTC25m

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 N94800 page for operator, model, and routing details .

Mode-S AD2D51 frequently asked

What is Mode-S code AD2D51?
AD2D51 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N94800.
Where is Mode-S AD2D51 registered?
Mode-S code AD2D51 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 AD2D51 broadcasting right now?
No active broadcast right now. Last signal was 26d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AD2D51, octal 53226521, decimal 11,349,329.
What flights does AD2D51 operate?
Mode-S AD2D51 has broadcast 2 distinct callsigns, including CAP401, N94800.