sensors Mode-S transponder

A6C39F

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N535GJ · BOMBARDIER Regional Jet CRJ-700 · operated by SKYWEST AIRLINES INC

Hex
A6C39F
Octal
51541637
Decimal
10,929,055
Country
US
Tail
N535GJ
Type
CRJ7
Photo of N535GJ
Broadcasting now · callsign GJS4557 · 35,000 ft
Flights observed
11
Distinct callsigns
8
Country
US
Last broadcast
21h ago

Current position

A6C39F is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A6C39F 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 8 distinct

Callsign Airline Flights Last seen
GJS4388 GoJet Airlines 2 2026-04-13
GJS4382 - 2 2026-04-13
GJS4381 - 2 2026-04-13
GJS4599 - 1 2026-04-13
GJS4483 - 1 2026-04-12
GJS4461 - 1 2026-04-12
GJS4449 - 1 2026-04-13
GJS4391 - 1 2026-04-14

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 GJS4391 - Apr 14, 05:15 UTCApr 14, 05:40 UTC25m
2026-04-13 GJS4388 ORD → YOW Apr 13, 22:20 UTCApr 13, 22:55 UTC35m
2026-04-13 GJS4388 ORD → YOW Apr 13, 21:12 UTCApr 13, 21:42 UTC30m
2026-04-13 GJS4381 - Apr 13, 20:00 UTCApr 13, 20:10 UTC10m
2026-04-13 GJS4381 BUF → BUF Apr 13, 18:17 UTCApr 13, 19:31 UTC1h 14m
2026-04-13 GJS4382 - Apr 13, 16:15 UTCApr 13, 17:20 UTC1h 5m
2026-04-13 GJS4382 - Apr 13, 16:03 UTCApr 13, 17:16 UTC1h 13m
2026-04-13 GJS4449 - Apr 13, 12:50 UTCApr 13, 14:40 UTC1h 50m
2026-04-13 GJS4599 - Apr 13, 01:50 UTCApr 13, 03:15 UTC1h 25m
2026-04-12 GJS4461 - Apr 12, 19:35 UTCApr 12, 20:32 UTC57m
2026-04-12 GJS4483 - Apr 12, 16:42 UTCApr 12, 17:39 UTC57m

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 N535GJ page for operator, model, and routing details .

Mode-S A6C39F frequently asked

What is Mode-S code A6C39F?
A6C39F is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N535GJ.
Where is Mode-S A6C39F registered?
Mode-S code A6C39F 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 A6C39F broadcasting right now?
Yes. Mode-S A6C39F is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A6C39F, octal 51541637, decimal 10,929,055.
What flights does A6C39F operate?
Mode-S A6C39F has broadcast 8 distinct callsigns, including GJS4388, GJS4382, GJS4381, GJS4599, GJS4483.