sensors Mode-S transponder

A9BDDC

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N727DD · ROBINSON R-22 Mariner · operated by ALBA AVIATION SERVICES INC

Hex
A9BDDC
Octal
52336734
Decimal
11,124,188
Country
US
Tail
N727DD
Type
R22
No current signal · last broadcast 1d ago
Flights observed
1
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9BDDC.

Country allocation

The ICAO 24-bit address A9BDDC 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
N727DD - 1 2026-04-13

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-13 N727DD - Apr 13, 19:50 UTCApr 13, 20:40 UTC50m

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 N727DD page for operator, model, and routing details .

Mode-S A9BDDC frequently asked

What is Mode-S code A9BDDC?
A9BDDC is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N727DD.
Where is Mode-S A9BDDC registered?
Mode-S code A9BDDC 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 A9BDDC 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 A9BDDC, octal 52336734, decimal 11,124,188.
What flights does A9BDDC operate?
Mode-S A9BDDC has broadcast 1 distinct callsign, including N727DD.