sensors Mode-S transponder

A66C9A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N513AF · PIPER PA-28-140/150/160/180 · operated by AMERIFLYERS OF TEXAS INC

Hex
A66C9A
Octal
51466232
Decimal
10,906,778
Country
US
Tail
N513AF
Type
P28A
No current signal · last broadcast 23h ago
Flights observed
8
Distinct callsigns
1
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A66C9A.

Country allocation

The ICAO 24-bit address A66C9A 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
N513AF - 8 2026-04-17

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-17 N513AF COI → COI Apr 17, 18:00 UTCApr 17, 18:35 UTC35m
2026-04-17 N513AF COI → COI Apr 17, 15:55 UTCApr 17, 16:30 UTC35m
2026-04-17 N513AF - Apr 17, 13:20 UTCApr 17, 15:15 UTC1h 54m
2026-04-17 N513AF - Apr 17, 12:05 UTCApr 17, 13:15 UTC1h 10m
2026-04-16 N513AF COI → COI Apr 16, 15:25 UTCApr 16, 16:10 UTC45m
2026-04-16 N513AF COI → COI Apr 16, 13:44 UTCApr 16, 14:50 UTC1h 5m
2026-04-15 N513AF - Apr 15, 20:15 UTCApr 15, 21:00 UTC45m
2026-04-14 N513AF - Apr 14, 13:55 UTCApr 14, 14:45 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 N513AF page for operator, model, and routing details .

Mode-S A66C9A frequently asked

What is Mode-S code A66C9A?
A66C9A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N513AF.
Where is Mode-S A66C9A registered?
Mode-S code A66C9A 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 A66C9A broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A66C9A, octal 51466232, decimal 10,906,778.
What flights does A66C9A operate?
Mode-S A66C9A has broadcast 1 distinct callsign, including N513AF.