Apparatus

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sensors Mode-S transponder

A9D7DD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N733TD · CESSNA 172 Skyhawk · operated by FRANTZEN ELIZABETH

Hex
A9D7DD
Octal
52353735
Decimal
11,130,845
Country
US
Tail
N733TD
Type
C172
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9D7DD.

Country allocation

The ICAO 24-bit address A9D7DD 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
N733TD - 7 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 N733TD - Apr 13, 23:15 UTCApr 13, 23:40 UTC25m
2026-04-13 N733TD HWO → HWO Apr 13, 20:35 UTCApr 13, 22:15 UTC1h 40m
2026-04-13 N733TD HWO → HWO Apr 13, 18:40 UTCApr 13, 19:45 UTC1h 5m
2026-04-13 N733TD - Apr 13, 16:15 UTCApr 13, 17:45 UTC1h 30m
2026-04-13 N733TD - Apr 13, 15:50 UTCApr 13, 17:45 UTC1h 55m
2026-04-13 N733TD - Apr 13, 15:00 UTCApr 13, 16:15 UTC1h 15m
2026-04-13 N733TD HWO → HWO Apr 13, 12:50 UTCApr 13, 14:15 UTC1h 25m

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 N733TD page for operator, model, and routing details .

Mode-S A9D7DD frequently asked

What is Mode-S code A9D7DD?
A9D7DD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N733TD.
Where is Mode-S A9D7DD registered?
Mode-S code A9D7DD 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 A9D7DD 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 A9D7DD, octal 52353735, decimal 11,130,845.
What flights does A9D7DD operate?
Mode-S A9D7DD has broadcast 1 distinct callsign, including N733TD.