sensors Mode-S transponder

A4A9DF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N4VW · CESSNA T210 Turbo Centurion · operated by PRONK GLEN R

Hex
A4A9DF
Octal
51124737
Decimal
10,791,391
Country
US
Tail
N4VW
Type
T210
No current signal · last broadcast 2d ago
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S A4A9DF.

Country allocation

The ICAO 24-bit address A4A9DF 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
N4VW - 6 2026-07-16

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-07-16 N4VW - Jul 16, 17:25 UTCJul 16, 19:55 UTC2h 30m
2026-07-13 N4VW - Jul 13, 16:05 UTCJul 13, 18:40 UTC2h 35m
2026-07-12 N4VW - Jul 12, 17:01 UTCJul 12, 20:15 UTC3h 15m
2026-07-11 N4VW - Jul 11, 18:25 UTCJul 11, 20:30 UTC2h 5m
2026-07-11 N4VW - Jul 11, 17:20 UTCJul 11, 17:50 UTC30m
2026-06-25 N4VW - Jun 25, 20:14 UTCJun 25, 20:30 UTC15m

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 N4VW page for operator, model, and routing details .

Mode-S A4A9DF frequently asked

What is Mode-S code A4A9DF?
A4A9DF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N4VW.
Where is Mode-S A4A9DF registered?
Mode-S code A4A9DF 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 A4A9DF broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4A9DF, octal 51124737, decimal 10,791,391.
What flights does A4A9DF operate?
Mode-S A4A9DF has broadcast 1 distinct callsign, including N4VW.