sensors Mode-S transponder

A91AF0

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N686QS · CESSNA 560XL Citation XLS · operated by NETJETS SALES INC

Hex
A91AF0
Octal
52215360
Decimal
11,082,480
Country
US
Tail
N686QS
Type
C56X
Photo of N686QS
No current signal · last broadcast 1d ago
Flights observed
9
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A91AF0.

Country allocation

The ICAO 24-bit address A91AF0 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
EJA686 NetJets 9 2026-04-13

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-13 EJA686 FOK → YDF Apr 13, 19:50 UTCApr 13, 20:00 UTC10m
2026-04-13 EJA686 FOK → YDF Apr 13, 18:40 UTCApr 13, 20:00 UTC1h 20m
2026-04-13 EJA686 FOK → YDF Apr 13, 16:15 UTCApr 13, 17:15 UTC1h 0m
2026-04-13 EJA686 FOK → YDF Apr 13, 15:50 UTCApr 13, 17:15 UTC1h 25m
2026-04-13 EJA686 FOK → YDF Apr 13, 15:20 UTCApr 13, 16:15 UTC55m
2026-04-13 EJA686 FOK → YDF Apr 13, 00:55 UTCApr 13, 02:35 UTC1h 40m
2026-04-12 EJA686 FOK → YDF Apr 12, 23:55 UTCApr 13, 00:15 UTC20m
2026-04-12 EJA686 FOK → YDF Apr 12, 20:00 UTCApr 12, 20:15 UTC15m
2026-04-12 EJA686 FOK → YDF Apr 12, 17:20 UTCApr 12, 17:35 UTC15m

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 N686QS page for operator, model, and routing details .

Mode-S A91AF0 frequently asked

What is Mode-S code A91AF0?
A91AF0 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N686QS.
Where is Mode-S A91AF0 registered?
Mode-S code A91AF0 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 A91AF0 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A91AF0, octal 52215360, decimal 11,082,480.
What flights does A91AF0 operate?
Mode-S A91AF0 has broadcast 1 distinct callsign, including EJA686.