sensors Mode-S transponder

A9DB04

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N734MK · CESSNA 172 Skyhawk · operated by FLYBY AVIATION LLC

Hex
A9DB04
Octal
52355404
Decimal
11,131,652
Country
US
Tail
N734MK
Type
C172
No current signal · last broadcast 9h ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
9h ago

Last known position

Most recent position reported by Mode-S A9DB04.

Country allocation

The ICAO 24-bit address A9DB04 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
N734MK - 7 2026-06-29

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-06-29 N734MK LGU → LGU Jun 29, 22:39 UTCJun 30, 00:00 UTC1h 20m
2026-06-28 N734MK - Jun 28, 21:50 UTCJun 28, 21:59 UTC10m
2026-06-28 N734MK - Jun 28, 20:09 UTCJun 28, 21:14 UTC1h 5m
2026-06-28 N734MK LGU → LGU Jun 28, 17:50 UTCJun 28, 19:44 UTC1h 55m
2026-06-11 N734MK - Jun 11, 15:25 UTCJun 11, 15:45 UTC20m
2026-06-10 N734MK LGU → LGU Jun 10, 16:05 UTCJun 10, 17:25 UTC1h 20m
2026-06-08 N734MK LGU → LGU Jun 8, 13:45 UTCJun 8, 14:20 UTC35m

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 N734MK page for operator, model, and routing details .

Mode-S A9DB04 frequently asked

What is Mode-S code A9DB04?
A9DB04 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N734MK.
Where is Mode-S A9DB04 registered?
Mode-S code A9DB04 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 A9DB04 broadcasting right now?
No active broadcast right now. Last signal was 9h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9DB04, octal 52355404, decimal 11,131,652.
What flights does A9DB04 operate?
Mode-S A9DB04 has broadcast 1 distinct callsign, including N734MK.