Apparatus

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sensors Mode-S transponder

A4AAE4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N40GF · PILATUS PC-12 · operated by N40 AIR LLC

Hex
A4AAE4
Octal
51125344
Decimal
10,791,652
Country
US
Tail
N40GF
Type
PC12
No current signal · last broadcast 8d ago
Flights observed
33
Distinct callsigns
1
Country
US
Last broadcast
8d ago

Last known position

Most recent position reported by Mode-S A4AAE4.

Country allocation

The ICAO 24-bit address A4AAE4 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
STT40 Air St. Thomas 33 2026-05-21

Recent flights last 33

DateFlightRouteTakeoffLandingDuration
2026-05-21 STT40 PHX → GTF May 21, 21:20 UTCMay 21, 21:50 UTC30m
2026-05-20 STT40 PHX → GTF May 20, 14:00 UTCMay 20, 14:30 UTC30m
2026-05-19 STT40 PHX → GTF May 19, 22:50 UTCMay 19, 23:25 UTC35m
2026-05-18 STT40 PHX → GTF May 18, 13:40 UTCMay 18, 14:10 UTC30m
2026-05-14 STT40 PHX → GTF May 14, 21:05 UTCMay 14, 21:30 UTC25m
2026-05-13 STT40 PHX → GTF May 13, 14:40 UTCMay 13, 15:10 UTC30m
2026-05-02 STT40 PHX → GTF May 2, 02:25 UTCMay 2, 03:25 UTC1h 0m
2026-05-02 STT40 PHX → GTF May 2, 01:00 UTCMay 2, 01:45 UTC45m
2026-04-30 STT40 PHX → GTF Apr 30, 03:45 UTCApr 30, 04:25 UTC40m
2026-04-30 STT40 PHX → GTF Apr 30, 02:15 UTCApr 30, 03:10 UTC55m
2026-04-22 STT40 PHX → GTF Apr 22, 18:10 UTCApr 22, 18:35 UTC25m
2026-04-20 STT40 PHX → GTF Apr 20, 16:35 UTCApr 20, 17:20 UTC45m
2026-04-20 STT40 PHX → GTF Apr 20, 15:15 UTCApr 20, 15:30 UTC15m
2026-04-20 STT40 PHX → GTF Apr 20, 01:40 UTCApr 20, 02:10 UTC30m
2026-04-19 STT40 PHX → GTF Apr 19, 23:05 UTCApr 19, 23:35 UTC30m
2026-04-19 STT40 PHX → GTF Apr 19, 17:35 UTCApr 19, 18:05 UTC30m
2026-04-19 STT40 PHX → GTF Apr 19, 15:15 UTCApr 19, 15:45 UTC30m
2026-04-19 STT40 PHX → GTF Apr 19, 00:25 UTCApr 19, 01:00 UTC35m
2026-04-18 STT40 PHX → GTF Apr 18, 22:40 UTCApr 18, 23:05 UTC25m
2026-04-18 STT40 PHX → GTF Apr 18, 20:30 UTCApr 18, 21:00 UTC30m
2026-04-18 STT40 PHX → GTF Apr 18, 14:20 UTCApr 18, 14:50 UTC30m
2026-04-18 STT40 PHX → GTF Apr 18, 00:00 UTCApr 18, 00:35 UTC35m
2026-04-17 STT40 PHX → GTF Apr 17, 14:10 UTCApr 17, 14:40 UTC30m
2026-04-16 STT40 PHX → GTF Apr 16, 19:25 UTCApr 16, 20:00 UTC35m
2026-04-16 STT40 PHX → GTF Apr 16, 18:30 UTCApr 16, 18:55 UTC25m
2026-04-16 STT40 PHX → GTF Apr 16, 15:30 UTCApr 16, 16:00 UTC30m
2026-04-16 STT40 PHX → GTF Apr 16, 13:54 UTCApr 16, 14:30 UTC35m
2026-04-15 STT40 PHX → GTF Apr 15, 21:30 UTCApr 15, 22:00 UTC30m
2026-04-15 STT40 PHX → GTF Apr 15, 20:20 UTCApr 15, 20:55 UTC35m
2026-04-13 STT40 PHX → GTF Apr 13, 00:20 UTCApr 13, 00:45 UTC25m
2026-04-12 STT40 PHX → GTF Apr 12, 23:55 UTCApr 13, 00:45 UTC50m
2026-04-12 STT40 PHX → GTF Apr 12, 18:45 UTCApr 12, 20:15 UTC1h 30m
2026-04-12 STT40 PHX → GTF Apr 12, 17:15 UTCApr 12, 18:10 UTC55m

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 N40GF page for operator, model, and routing details .

Mode-S A4AAE4 frequently asked

What is Mode-S code A4AAE4?
A4AAE4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N40GF.
Where is Mode-S A4AAE4 registered?
Mode-S code A4AAE4 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 A4AAE4 broadcasting right now?
No active broadcast right now. Last signal was 8d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4AAE4, octal 51125344, decimal 10,791,652.
What flights does A4AAE4 operate?
Mode-S A4AAE4 has broadcast 1 distinct callsign, including STT40.