Apparatus

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sensors Mode-S transponder

A9D81C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N733VS · CESSNA 172 Skyhawk · operated by CLEMSON FLYING CLUB INC

Hex
A9D81C
Octal
52354034
Decimal
11,130,908
Country
US
Tail
N733VS
Type
C172
No current signal · last broadcast 1d ago
Flights observed
143
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9D81C.

Country allocation

The ICAO 24-bit address A9D81C 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
N733VS - 143 2026-07-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-16 N733VS - Jul 16, 20:25 UTCJul 16, 20:45 UTC20m
2026-07-16 N733VS - Jul 16, 19:30 UTCJul 16, 19:40 UTC10m
2026-07-15 N733VS - Jul 15, 19:40 UTCJul 15, 20:10 UTC30m
2026-07-03 N733VS - Jul 3, 18:55 UTCJul 3, 19:45 UTC50m
2026-07-03 N733VS - Jul 3, 16:40 UTCJul 3, 17:25 UTC45m
2026-07-02 N733VS - Jul 2, 12:35 UTCJul 2, 12:55 UTC20m
2026-07-01 N733VS - Jul 1, 22:40 UTCJul 1, 22:55 UTC15m
2026-07-01 N733VS - Jul 1, 16:05 UTCJul 1, 17:45 UTC1h 40m
2026-06-26 N733VS - Jun 26, 14:59 UTCJun 26, 16:30 UTC1h 30m
2026-06-26 N733VS - Jun 26, 12:59 UTCJun 26, 13:55 UTC55m
2026-06-25 N733VS - Jun 25, 15:10 UTCJun 25, 16:09 UTC1h 0m
2026-06-23 N733VS - Jun 23, 15:15 UTCJun 23, 16:14 UTC1h 0m
2026-06-23 N733VS CEU → CEU Jun 23, 12:40 UTCJun 23, 13:15 UTC35m
2026-06-22 N733VS - Jun 22, 12:49 UTCJun 22, 13:35 UTC45m
2026-06-20 N733VS - Jun 20, 15:09 UTCJun 20, 16:29 UTC1h 20m
2026-06-17 N733VS - Jun 17, 19:35 UTCJun 17, 20:25 UTC50m
2026-06-17 N733VS - Jun 17, 14:10 UTCJun 17, 14:30 UTC20m
2026-06-14 N733VS - Jun 14, 14:05 UTCJun 14, 15:25 UTC1h 20m
2026-06-13 N733VS - Jun 13, 18:55 UTCJun 13, 19:20 UTC25m
2026-06-13 N733VS - Jun 13, 15:10 UTCJun 13, 16:05 UTC55m
2026-06-11 N733VS - Jun 11, 21:55 UTCJun 11, 22:30 UTC35m
2026-06-11 N733VS - Jun 11, 19:05 UTCJun 11, 19:50 UTC45m
2026-06-10 N733VS CEU → CEU Jun 10, 17:00 UTCJun 10, 18:25 UTC1h 25m
2026-06-08 N733VS - Jun 8, 14:00 UTCJun 8, 15:15 UTC1h 15m
2026-06-08 N733VS - Jun 8, 00:05 UTCJun 8, 00:35 UTC30m
2026-06-07 N733VS - Jun 7, 22:55 UTCJun 7, 23:15 UTC20m
2026-06-07 N733VS - Jun 7, 17:00 UTCJun 7, 17:50 UTC50m
2026-06-07 N733VS - Jun 7, 14:10 UTCJun 7, 15:15 UTC1h 5m
2026-06-06 N733VS - Jun 6, 20:05 UTCJun 6, 21:44 UTC1h 40m
2026-06-06 N733VS - Jun 6, 18:39 UTCJun 6, 18:55 UTC15m
2026-06-06 N733VS CEU → CEU Jun 6, 14:20 UTCJun 6, 15:25 UTC1h 5m
2026-06-06 N733VS - Jun 6, 12:14 UTCJun 6, 13:20 UTC1h 5m
2026-06-05 N733VS - Jun 5, 17:05 UTCJun 5, 17:55 UTC50m
2026-06-05 N733VS - Jun 5, 15:30 UTCJun 5, 16:15 UTC45m
2026-06-05 N733VS - Jun 5, 12:55 UTCJun 5, 14:10 UTC1h 15m
2026-06-04 N733VS - Jun 4, 15:45 UTCJun 4, 16:45 UTC1h 0m
2026-06-03 N733VS - Jun 3, 21:20 UTCJun 3, 22:20 UTC1h 0m
2026-06-03 N733VS - Jun 3, 19:10 UTCJun 3, 19:45 UTC35m
2026-06-03 N733VS - Jun 3, 18:10 UTCJun 3, 18:40 UTC30m
2026-06-03 N733VS - Jun 3, 15:25 UTCJun 3, 16:45 UTC1h 20m
2026-06-03 N733VS - Jun 3, 12:40 UTCJun 3, 13:30 UTC50m
2026-06-02 N733VS - Jun 2, 21:10 UTCJun 2, 22:30 UTC1h 20m
2026-06-01 N733VS - Jun 1, 22:45 UTCJun 1, 23:25 UTC40m
2026-06-01 N733VS - Jun 1, 17:30 UTCJun 1, 18:05 UTC35m
2026-06-01 N733VS - Jun 1, 13:55 UTCJun 1, 14:45 UTC50m
2026-05-30 N733VS - May 30, 14:30 UTCMay 30, 15:45 UTC1h 15m
2026-05-29 N733VS - May 29, 21:20 UTCMay 29, 22:00 UTC40m
2026-05-17 N733VS - May 17, 17:45 UTCMay 17, 18:25 UTC40m
2026-05-16 N733VS - May 16, 18:30 UTCMay 16, 18:40 UTC10m
2026-05-16 N733VS - May 16, 12:50 UTCMay 16, 13:41 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 N733VS page for operator, model, and routing details .

Mode-S A9D81C frequently asked

What is Mode-S code A9D81C?
A9D81C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N733VS.
Where is Mode-S A9D81C registered?
Mode-S code A9D81C 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 A9D81C 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 A9D81C, octal 52354034, decimal 11,130,908.
What flights does A9D81C operate?
Mode-S A9D81C has broadcast 1 distinct callsign, including N733VS.