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sensors Mode-S transponder

ADF418

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N999AF · CESSNA 172 Skyhawk · operated by THREE FOUR JULIET LLC

Hex
ADF418
Octal
53372030
Decimal
11,400,216
Country
US
Tail
N999AF
Type
C172
No current signal · last broadcast Jul 26, 15:35 UTC
Flights observed
157
Distinct callsigns
1
Country
US
Last broadcast
Jul 26, 15:35 UTC

Last known position

Most recent position reported by Mode-S ADF418.

Country allocation

The ICAO 24-bit address ADF418 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
N999AF - 157 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 N999AF - Jul 26, 14:50 UTCJul 26, 15:35 UTC45m
2026-07-26 N999AF - Jul 26, 12:55 UTCJul 26, 14:00 UTC1h 5m
2026-07-26 N999AF - Jul 26, 01:50 UTCJul 26, 02:35 UTC45m
2026-07-25 N999AF - Jul 25, 22:00 UTCJul 25, 22:15 UTC15m
2026-07-25 N999AF - Jul 25, 20:00 UTCJul 25, 20:45 UTC45m
2026-07-25 N999AF - Jul 25, 17:55 UTCJul 25, 18:40 UTC45m
2026-07-25 N999AF - Jul 25, 15:55 UTCJul 25, 16:50 UTC55m
2026-07-25 N999AF - Jul 25, 14:15 UTCJul 25, 14:50 UTC35m
2026-07-25 N999AF FDK → FDK Jul 25, 12:00 UTCJul 25, 12:55 UTC55m
2026-07-24 N999AF - Jul 24, 23:15 UTCJul 24, 23:55 UTC40m
2026-07-24 N999AF - Jul 24, 21:25 UTCJul 24, 21:50 UTC25m
2026-07-24 N999AF - Jul 24, 19:00 UTCJul 24, 19:50 UTC50m
2026-07-24 N999AF - Jul 24, 16:50 UTCJul 24, 17:45 UTC55m
2026-07-24 N999AF FDK → FDK Jul 24, 15:00 UTCJul 24, 15:30 UTC30m
2026-07-24 N999AF - Jul 24, 12:05 UTCJul 24, 14:05 UTC2h 0m
2026-07-23 N999AF - Jul 23, 22:55 UTCJul 23, 23:40 UTC45m
2026-07-23 N999AF - Jul 23, 17:55 UTCJul 23, 18:40 UTC45m
2026-07-23 N999AF - Jul 23, 14:05 UTCJul 23, 15:15 UTC1h 10m
2026-07-22 N999AF - Jul 22, 22:55 UTCJul 22, 23:30 UTC35m
2026-07-22 N999AF FDK → FDK Jul 22, 20:50 UTCJul 22, 21:40 UTC50m
2026-07-22 N999AF - Jul 22, 14:45 UTCJul 22, 15:35 UTC50m
2026-07-22 N999AF FDK → FDK Jul 22, 12:15 UTCJul 22, 13:15 UTC1h 0m
2026-07-20 N999AF FDK → FDK Jul 20, 21:35 UTCJul 20, 22:20 UTC45m
2026-07-20 N999AF - Jul 20, 19:35 UTCJul 20, 20:00 UTC25m
2026-07-20 N999AF - Jul 20, 15:55 UTCJul 20, 16:25 UTC30m
2026-07-20 N999AF - Jul 20, 13:55 UTCJul 20, 14:50 UTC55m
2026-07-19 N999AF - Jul 19, 22:55 UTCJul 20, 00:10 UTC1h 15m
2026-07-19 N999AF - Jul 19, 20:25 UTCJul 19, 20:35 UTC10m
2026-07-19 N999AF - Jul 19, 12:05 UTCJul 19, 13:10 UTC1h 5m
2026-07-16 N999AF - Jul 16, 21:00 UTCJul 16, 21:19 UTC20m
2026-07-16 N999AF - Jul 16, 18:50 UTCJul 16, 19:50 UTC1h 0m
2026-07-16 N999AF - Jul 16, 15:55 UTCJul 16, 16:09 UTC15m
2026-07-16 N999AF FDK → FDK Jul 16, 14:05 UTCJul 16, 14:50 UTC45m
2026-07-16 N999AF FDK → FDK Jul 16, 12:00 UTCJul 16, 12:40 UTC40m
2026-07-16 N999AF - Jul 16, 00:20 UTCJul 16, 00:35 UTC15m
2026-07-15 N999AF - Jul 15, 22:55 UTCJul 15, 23:15 UTC20m
2026-07-15 N999AF - Jul 15, 21:05 UTCJul 15, 21:50 UTC45m
2026-07-15 N999AF - Jul 15, 19:20 UTCJul 15, 19:35 UTC15m
2026-07-15 N999AF - Jul 15, 17:55 UTCJul 15, 18:05 UTC10m
2026-07-15 N999AF - Jul 15, 16:00 UTCJul 15, 16:55 UTC55m
2026-07-15 N999AF - Jul 15, 14:05 UTCJul 15, 14:35 UTC30m
2026-07-15 N999AF - Jul 15, 01:30 UTCJul 15, 03:25 UTC1h 55m
2026-07-14 N999AF - Jul 14, 22:55 UTCJul 14, 23:25 UTC30m
2026-07-14 N999AF - Jul 14, 20:50 UTCJul 14, 21:45 UTC55m
2026-07-14 N999AF - Jul 14, 17:15 UTCJul 14, 18:55 UTC1h 40m
2026-07-14 N999AF - Jul 14, 15:00 UTCJul 14, 15:55 UTC55m
2026-07-13 N999AF - Jul 13, 23:15 UTCJul 14, 00:35 UTC1h 20m
2026-07-13 N999AF - Jul 13, 20:45 UTCJul 13, 21:45 UTC1h 0m
2026-07-13 N999AF - Jul 13, 17:50 UTCJul 13, 18:55 UTC1h 5m
2026-07-13 N999AF - Jul 13, 14:40 UTCJul 13, 16:00 UTC1h 20m

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 N999AF page for operator, model, and routing details .

Mode-S ADF418 frequently asked

What is Mode-S code ADF418?
ADF418 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N999AF.
Where is Mode-S ADF418 registered?
Mode-S code ADF418 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 ADF418 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 15:35 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ADF418, octal 53372030, decimal 11,400,216.
What flights does ADF418 operate?
Mode-S ADF418 has broadcast 1 distinct callsign, including N999AF.