sensors Mode-S transponder

AD50C9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N957XV · operated by AMERICAN AIRLINES INC

Hex
AD50C9
Octal
53250311
Decimal
11,358,409
Country
US
Tail
N957XV
Type
A21N
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
3
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AD50C9.

Country allocation

The ICAO 24-bit address AD50C9 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 3 distinct

Callsign Airline Flights Last seen
AAL2109 American Airlines 3 2026-04-13
AAL757 - 2 2026-04-13
AAL1559 - 2 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 AAL1559 - Apr 13, 22:45 UTCApr 13, 23:15 UTC30m
2026-04-13 AAL1559 - Apr 13, 20:25 UTCApr 13, 22:27 UTC2h 2m
2026-04-13 AAL2109 LAX → DCA Apr 13, 16:15 UTCApr 13, 18:40 UTC2h 25m
2026-04-13 AAL2109 LAX → DCA Apr 13, 16:05 UTCApr 13, 16:15 UTC10m
2026-04-13 AAL2109 LAX → DCA Apr 13, 12:25 UTCApr 13, 14:50 UTC2h 25m
2026-04-13 AAL757 - Apr 13, 00:20 UTCApr 13, 03:45 UTC3h 25m
2026-04-12 AAL757 - Apr 12, 18:55 UTCApr 12, 20:15 UTC1h 20m

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 N957XV page for operator, model, and routing details .

Mode-S AD50C9 frequently asked

What is Mode-S code AD50C9?
AD50C9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N957XV.
Where is Mode-S AD50C9 registered?
Mode-S code AD50C9 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 AD50C9 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 AD50C9, octal 53250311, decimal 11,358,409.
What flights does AD50C9 operate?
Mode-S AD50C9 has broadcast 3 distinct callsigns, including AAL2109, AAL757, AAL1559.