sensors Mode-S transponder

A19C4B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N20230 · CESSNA 172 Skyhawk · operated by CESSNA 20230 LLC

Hex
A19C4B
Octal
50316113
Decimal
10,591,307
Country
US
Tail
N20230
Type
C172
No current signal · last broadcast 16h ago
Flights observed
21
Distinct callsigns
1
Country
US
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S A19C4B.

Country allocation

The ICAO 24-bit address A19C4B 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
N20230 - 21 2026-04-18

Recent flights last 21

DateFlightRouteTakeoffLandingDuration
2026-04-18 N20230 - Apr 18, 00:35 UTCApr 18, 01:20 UTC45m
2026-04-17 N20230 - Apr 17, 21:55 UTCApr 17, 23:20 UTC1h 25m
2026-04-17 N20230 - Apr 17, 20:50 UTCApr 17, 21:00 UTC10m
2026-04-17 N20230 - Apr 17, 17:50 UTCApr 17, 18:00 UTC10m
2026-04-16 N20230 - Apr 16, 22:30 UTCApr 16, 23:00 UTC30m
2026-04-16 N20230 - Apr 16, 20:15 UTCApr 16, 20:25 UTC10m
2026-04-16 N20230 - Apr 16, 18:10 UTCApr 16, 18:25 UTC15m
2026-04-16 N20230 STS → NOT Apr 16, 17:44 UTCApr 16, 18:05 UTC20m
2026-04-15 N20230 - Apr 15, 23:25 UTCApr 16, 00:10 UTC45m
2026-04-15 N20230 - Apr 15, 21:05 UTCApr 15, 22:00 UTC55m
2026-04-15 N20230 - Apr 15, 20:30 UTCApr 15, 21:00 UTC30m
2026-04-15 N20230 - Apr 15, 19:05 UTCApr 15, 19:15 UTC10m
2026-04-15 N20230 - Apr 15, 18:15 UTCApr 15, 19:00 UTC45m
2026-04-15 N20230 - Apr 15, 01:55 UTCApr 15, 02:05 UTC10m
2026-04-14 N20230 - Apr 14, 22:55 UTCApr 14, 23:40 UTC45m
2026-04-14 N20230 - Apr 14, 22:40 UTCApr 14, 22:50 UTC10m
2026-04-14 N20230 - Apr 14, 20:55 UTCApr 14, 21:05 UTC10m
2026-04-14 N20230 - Apr 14, 20:30 UTCApr 14, 20:50 UTC20m
2026-04-14 N20230 - Apr 14, 18:20 UTCApr 14, 18:45 UTC25m
2026-04-13 N20230 - Apr 13, 23:15 UTCApr 13, 23:40 UTC25m
2026-04-13 N20230 - Apr 13, 18:55 UTCApr 13, 19:05 UTC10m

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 N20230 page for operator, model, and routing details .

Mode-S A19C4B frequently asked

What is Mode-S code A19C4B?
A19C4B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N20230.
Where is Mode-S A19C4B registered?
Mode-S code A19C4B 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 A19C4B broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A19C4B, octal 50316113, decimal 10,591,307.
What flights does A19C4B operate?
Mode-S A19C4B has broadcast 1 distinct callsign, including N20230.