Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A9C2B3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N728QS · BOMBARDIER BD-100 Challenger 350 · operated by NETJETS SALES INC, DF AVIATION LLC, FLAWS JAMES, GIANNANDREA JOHN, NEWSTONE CAPITAL PARTNERS LLC, PSV SERVICES LLC

Hex
A9C2B3
Octal
52341263
Decimal
11,125,427
Country
US
Tail
N728QS
Type
CL35
No current signal · last broadcast 1d ago
Flights observed
108
Distinct callsigns
2
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9C2B3.

Country allocation

The ICAO 24-bit address A9C2B3 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 2 distinct

Callsign Airline Flights Last seen
EJA728 NetJets 100 2026-05-29
N728QS - 8 2026-05-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 EJA728 STS → SJC May 29, 00:55 UTCMay 29, 04:30 UTC3h 35m
2026-05-28 EJA728 STS → SJC May 28, 21:05 UTCMay 28, 21:30 UTC25m
2026-05-28 EJA728 STS → SJC May 28, 16:50 UTCMay 28, 18:50 UTC2h 0m
2026-05-27 EJA728 STS → SJC May 27, 20:50 UTCMay 27, 21:35 UTC45m
2026-05-27 EJA728 STS → SJC May 27, 14:10 UTCMay 27, 19:45 UTC5h 35m
2026-05-27 EJA728 STS → SJC May 27, 12:05 UTCMay 27, 12:25 UTC20m
2026-05-26 N728QS - May 26, 19:20 UTCMay 26, 19:45 UTC25m
2026-05-26 N728QS - May 26, 15:14 UTCMay 26, 15:45 UTC30m
2026-05-25 EJA728 STS → SJC May 25, 22:15 UTCMay 25, 22:34 UTC20m
2026-05-25 EJA728 STS → SJC May 25, 18:45 UTCMay 25, 21:24 UTC2h 39m
2026-05-25 EJA728 STS → SJC May 25, 14:35 UTCMay 25, 17:35 UTC3h 0m
2026-05-24 EJA728 STS → SJC May 24, 20:25 UTCMay 24, 21:50 UTC1h 25m
2026-05-24 EJA728 STS → SJC May 24, 16:15 UTCMay 24, 19:15 UTC3h 0m
2026-05-24 EJA728 STS → SJC May 24, 14:00 UTCMay 24, 14:20 UTC20m
2026-05-23 EJA728 STS → SJC May 23, 19:55 UTCMay 23, 20:45 UTC50m
2026-05-23 EJA728 STS → SJC May 23, 15:30 UTCMay 23, 19:10 UTC3h 41m
2026-05-23 EJA728 STS → SJC May 23, 12:55 UTCMay 23, 13:50 UTC55m
2026-05-22 EJA728 STS → SJC May 22, 18:50 UTCMay 22, 21:15 UTC2h 25m
2026-05-22 EJA728 STS → SJC May 22, 14:05 UTCMay 22, 15:55 UTC1h 50m
2026-05-21 EJA728 STS → SJC May 21, 21:05 UTCMay 21, 22:00 UTC55m
2026-05-21 EJA728 STS → SJC May 21, 18:00 UTCMay 21, 18:45 UTC45m
2026-05-21 EJA728 STS → SJC May 21, 02:25 UTCMay 21, 05:30 UTC3h 5m
2026-05-19 EJA728 STS → SJC May 19, 22:05 UTCMay 19, 22:55 UTC50m
2026-05-19 EJA728 STS → SJC May 19, 19:40 UTCMay 19, 20:50 UTC1h 10m
2026-05-19 EJA728 STS → SJC May 19, 18:00 UTCMay 19, 18:15 UTC15m
2026-05-19 EJA728 STS → SJC May 19, 15:40 UTCMay 19, 17:25 UTC1h 45m
2026-05-19 EJA728 STS → SJC May 19, 12:35 UTCMay 19, 13:55 UTC1h 20m
2026-05-18 EJA728 STS → SJC May 18, 22:20 UTCMay 18, 22:50 UTC30m
2026-05-18 EJA728 STS → SJC May 18, 20:40 UTCMay 18, 21:35 UTC55m
2026-05-18 EJA728 STS → SJC May 18, 17:15 UTCMay 18, 17:50 UTC35m
2026-05-18 EJA728 STS → SJC May 18, 14:55 UTCMay 18, 15:45 UTC50m
2026-05-18 EJA728 STS → SJC May 18, 13:35 UTCMay 18, 14:15 UTC40m
2026-05-17 EJA728 STS → SJC May 17, 23:20 UTCMay 17, 23:50 UTC30m
2026-05-17 EJA728 STS → SJC May 17, 16:50 UTCMay 17, 22:40 UTC5h 50m
2026-05-17 EJA728 STS → SJC May 17, 15:35 UTCMay 17, 16:20 UTC45m
2026-05-16 EJA728 STS → SJC May 16, 18:25 UTCMay 16, 19:10 UTC45m
2026-05-16 EJA728 STS → SJC May 16, 15:55 UTCMay 16, 16:35 UTC40m
2026-05-15 EJA728 STS → SJC May 15, 21:55 UTCMay 15, 23:00 UTC1h 5m
2026-05-15 EJA728 STS → SJC May 15, 12:50 UTCMay 15, 16:00 UTC3h 9m
2026-05-14 EJA728 STS → SJC May 14, 21:55 UTCMay 14, 22:25 UTC30m
2026-05-14 EJA728 STS → SJC May 14, 19:30 UTCMay 14, 20:45 UTC1h 15m
2026-05-14 EJA728 STS → SJC May 14, 14:01 UTCMay 14, 16:20 UTC2h 20m
2026-05-13 EJA728 STS → SJC May 13, 20:05 UTCMay 13, 23:10 UTC3h 5m
2026-05-13 EJA728 STS → SJC May 13, 15:15 UTCMay 13, 18:35 UTC3h 20m
2026-05-12 EJA728 STS → SJC May 12, 21:10 UTCMay 12, 22:45 UTC1h 35m
2026-05-12 EJA728 STS → SJC May 12, 18:05 UTCMay 12, 19:00 UTC55m
2026-05-12 EJA728 STS → SJC May 12, 16:05 UTCMay 12, 16:55 UTC50m
2026-05-09 EJA728 STS → SJC May 9, 18:40 UTCMay 9, 19:30 UTC50m
2026-05-08 EJA728 STS → SJC May 8, 23:55 UTCMay 9, 01:50 UTC1h 55m
2026-05-08 EJA728 STS → SJC May 8, 21:50 UTCMay 8, 22:05 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 N728QS page for operator, model, and routing details .

Mode-S A9C2B3 frequently asked

What is Mode-S code A9C2B3?
A9C2B3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N728QS.
Where is Mode-S A9C2B3 registered?
Mode-S code A9C2B3 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 A9C2B3 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 A9C2B3, octal 52341263, decimal 11,125,427.
What flights does A9C2B3 operate?
Mode-S A9C2B3 has broadcast 2 distinct callsigns, including EJA728, N728QS.