sensors Mode-S transponder

A8BF72

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N663AV · operated by CIRRUS DESIGN CORP

Hex
A8BF72
Octal
52137562
Decimal
11,059,058
Country
US
Tail
N663AV
Type
SR20
No current signal · last broadcast 23h ago
Flights observed
5
Distinct callsigns
1
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A8BF72.

Country allocation

The ICAO 24-bit address A8BF72 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
VAR663 - 5 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 VAR663 GYR → GYR Apr 13, 22:50 UTCApr 13, 23:10 UTC20m
2026-04-13 VAR663 - Apr 13, 19:50 UTCApr 13, 20:45 UTC55m
2026-04-13 VAR663 - Apr 13, 18:45 UTCApr 13, 20:10 UTC1h 25m
2026-04-13 VAR663 BXK → GYR Apr 13, 16:15 UTCApr 13, 17:20 UTC1h 5m
2026-04-13 VAR663 - Apr 13, 15:45 UTCApr 13, 16:15 UTC30m

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 N663AV page for operator, model, and routing details .

Mode-S A8BF72 frequently asked

What is Mode-S code A8BF72?
A8BF72 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N663AV.
Where is Mode-S A8BF72 registered?
Mode-S code A8BF72 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 A8BF72 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 A8BF72, octal 52137562, decimal 11,059,058.
What flights does A8BF72 operate?
Mode-S A8BF72 has broadcast 1 distinct callsign, including VAR663.