sensors Mode-S transponder

A1CF6B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N2157J · AIRBUS A-321neo · operated by JETBLUE AIRWAYS CORP

Hex
A1CF6B
Octal
50347553
Decimal
10,604,395
Country
US
Tail
N2157J
Type
A21N
Broadcasting now · callsign JBU1124 · 35,000 ft
Flights observed
8
Distinct callsigns
4
Country
US
Last broadcast
23h ago

Current position

A1CF6B is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A1CF6B 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 4 distinct

Callsign Airline Flights Last seen
JBU115 JetBlue Airways 4 2026-04-13
JBU524 - 2 2026-04-13
JBU2223 - 1 2026-04-12
JBU1216 - 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 JBU1216 - Apr 13, 22:40 UTCApr 13, 23:45 UTC1h 5m
2026-04-13 JBU115 JFK → MSY Apr 13, 19:55 UTCApr 13, 20:55 UTC1h 0m
2026-04-13 JBU115 JFK → MSY Apr 13, 16:15 UTCApr 13, 20:10 UTC3h 55m
2026-04-13 JBU115 JFK → MSY Apr 13, 15:50 UTCApr 13, 19:45 UTC3h 55m
2026-04-13 JBU115 JFK → MSY Apr 13, 14:55 UTCApr 13, 16:15 UTC1h 20m
2026-04-13 JBU524 - Apr 13, 00:20 UTCApr 13, 01:10 UTC50m
2026-04-12 JBU524 - Apr 12, 23:55 UTCApr 13, 01:10 UTC1h 15m
2026-04-12 JBU2223 - Apr 12, 17:15 UTCApr 12, 18:30 UTC1h 15m

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 N2157J page for operator, model, and routing details .

Mode-S A1CF6B frequently asked

What is Mode-S code A1CF6B?
A1CF6B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N2157J.
Where is Mode-S A1CF6B registered?
Mode-S code A1CF6B 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 A1CF6B broadcasting right now?
Yes. Mode-S A1CF6B is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1CF6B, octal 50347553, decimal 10,604,395.
What flights does A1CF6B operate?
Mode-S A1CF6B has broadcast 4 distinct callsigns, including JBU115, JBU524, JBU2223, JBU1216.