sensors Mode-S transponder

A9D85A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N733YD · ZENAIR CH-801 Stol · operated by MCNAIR SAMUEL S

Hex
A9D85A
Octal
52354132
Decimal
11,130,970
Country
US
Tail
N733YD
Type
CH80
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 A9D85A.

Country allocation

The ICAO 24-bit address A9D85A 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
N733YD - 5 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 N733YD - Apr 13, 16:15 UTCApr 13, 16:45 UTC30m
2026-04-13 N733YD - Apr 13, 16:00 UTCApr 13, 16:15 UTC15m
2026-04-13 N733YD - Apr 13, 12:20 UTCApr 13, 15:05 UTC2h 45m
2026-04-13 N733YD - Apr 13, 11:55 UTCApr 13, 15:05 UTC3h 10m
2026-04-13 N733YD - Apr 13, 11:05 UTCApr 13, 12:15 UTC1h 10m

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 N733YD page for operator, model, and routing details .

Mode-S A9D85A frequently asked

What is Mode-S code A9D85A?
A9D85A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N733YD.
Where is Mode-S A9D85A registered?
Mode-S code A9D85A 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 A9D85A 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 A9D85A, octal 52354132, decimal 11,130,970.
What flights does A9D85A operate?
Mode-S A9D85A has broadcast 1 distinct callsign, including N733YD.