sensors Mode-S transponder

A19CD9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N20272 · CESSNA 172 Skyhawk · operated by SOUND AEROSPACE LLC

Hex
A19CD9
Octal
50316331
Decimal
10,591,449
Country
US
Tail
N20272
Type
C172
No current signal · last broadcast Jul 25, 18:20 UTC
Flights observed
30
Distinct callsigns
1
Country
US
Last broadcast
Jul 25, 18:20 UTC

Last known position

Most recent position reported by Mode-S A19CD9.

Country allocation

The ICAO 24-bit address A19CD9 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
N20272 - 30 2026-07-25

Recent flights last 30

DateFlightRouteTakeoffLandingDuration
2026-07-25 N20272 - Jul 25, 17:50 UTCJul 25, 18:20 UTC30m
2026-07-25 N20272 - Jul 25, 13:05 UTCJul 25, 13:35 UTC30m
2026-07-22 N20272 - Jul 22, 14:55 UTCJul 22, 15:35 UTC40m
2026-07-21 N20272 - Jul 21, 19:25 UTCJul 21, 19:35 UTC10m
2026-07-20 N20272 - Jul 20, 15:15 UTCJul 20, 16:15 UTC1h 0m
2026-06-30 N20272 - Jun 30, 03:05 UTCJun 30, 03:20 UTC15m
2026-06-28 N20272 COS → APA Jun 28, 07:05 UTCJun 28, 07:54 UTC50m
2026-06-28 N20272 - Jun 28, 05:24 UTCJun 28, 06:20 UTC55m
2026-06-22 N20272 - Jun 22, 18:44 UTCJun 22, 19:09 UTC25m
2026-06-22 N20272 - Jun 22, 13:10 UTCJun 22, 15:29 UTC2h 20m
2026-06-18 N20272 - Jun 18, 15:00 UTCJun 18, 17:25 UTC2h 25m
2026-06-18 N20272 - Jun 18, 11:35 UTCJun 18, 12:15 UTC40m
2026-06-16 N20272 - Jun 16, 12:45 UTCJun 16, 13:44 UTC1h 0m
2026-06-15 N20272 - Jun 15, 13:40 UTCJun 15, 14:30 UTC50m
2026-06-13 N20272 - Jun 13, 12:15 UTCJun 13, 13:15 UTC1h 0m
2026-06-03 N20272 - Jun 3, 15:10 UTCJun 3, 15:20 UTC10m
2026-06-03 N20272 - Jun 3, 13:35 UTCJun 3, 13:50 UTC15m
2026-06-01 N20272 - Jun 1, 12:25 UTCJun 1, 13:35 UTC1h 10m
2026-05-28 N20272 - May 28, 11:55 UTCMay 28, 13:00 UTC1h 5m
2026-05-27 N20272 - May 27, 12:55 UTCMay 27, 14:55 UTC2h 0m
2026-05-23 N20272 - May 23, 15:25 UTCMay 23, 16:45 UTC1h 20m
2026-05-13 N20272 - May 13, 15:40 UTCMay 13, 16:15 UTC35m
2026-05-13 N20272 - May 13, 14:30 UTCMay 13, 15:05 UTC35m
2026-05-07 N20272 - May 7, 15:10 UTCMay 7, 16:20 UTC1h 10m
2026-04-25 N20272 - Apr 25, 16:30 UTCApr 25, 17:15 UTC45m
2026-04-24 N20272 - Apr 24, 16:45 UTCApr 24, 17:00 UTC15m
2026-04-21 N20272 - Apr 21, 14:50 UTCApr 21, 15:51 UTC1h 0m
2026-04-19 N20272 - Apr 19, 17:00 UTCApr 19, 17:40 UTC40m
2026-04-14 N20272 - Apr 14, 14:50 UTCApr 14, 15:25 UTC35m
2026-04-14 N20272 - Apr 14, 14:30 UTCApr 14, 14:45 UTC15m

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 N20272 page for operator, model, and routing details .

Mode-S A19CD9 frequently asked

What is Mode-S code A19CD9?
A19CD9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N20272.
Where is Mode-S A19CD9 registered?
Mode-S code A19CD9 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 A19CD9 broadcasting right now?
No active broadcast right now. Last signal was Jul 25, 18:20 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A19CD9, octal 50316331, decimal 10,591,449.
What flights does A19CD9 operate?
Mode-S A19CD9 has broadcast 1 distinct callsign, including N20272.