sensors Mode-S transponder

ACF54F

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N934JB · AIRBUS A-321 · operated by JETBLUE AIRWAYS CORP

Hex
ACF54F
Octal
53172517
Decimal
11,334,991
Country
US
Tail
N934JB
Type
A321
Photo of N934JB
Broadcasting now · callsign JBU1588 · 35,050 ft
Flights observed
10
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Current position

ACF54F is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address ACF54F 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
JBU934 - 3 2026-04-13
JBU933 - 3 2026-04-13
JBU387 - 3 2026-04-13
JBU900 JetBlue Airways 1 2026-04-13

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-13 JBU900 FLL → BOS Apr 13, 21:25 UTCApr 13, 23:40 UTC2h 15m
2026-04-13 JBU387 - Apr 13, 16:15 UTCApr 13, 19:40 UTC3h 25m
2026-04-13 JBU387 - Apr 13, 15:50 UTCApr 13, 19:40 UTC3h 50m
2026-04-13 JBU387 - Apr 13, 13:30 UTCApr 13, 16:15 UTC2h 45m
2026-04-13 JBU934 - Apr 13, 08:20 UTCApr 13, 10:10 UTC1h 50m
2026-04-13 JBU934 CIN → BOS Apr 13, 07:55 UTCApr 13, 10:10 UTC2h 15m
2026-04-13 JBU934 - Apr 13, 05:20 UTCApr 13, 08:15 UTC2h 55m
2026-04-13 JBU933 - Apr 13, 00:20 UTCApr 13, 00:35 UTC15m
2026-04-12 JBU933 - Apr 12, 23:55 UTCApr 13, 00:35 UTC40m
2026-04-12 JBU933 - Apr 12, 18:10 UTCApr 12, 20:15 UTC2h 5m

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 N934JB page for operator, model, and routing details .

Mode-S ACF54F frequently asked

What is Mode-S code ACF54F?
ACF54F is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N934JB.
Where is Mode-S ACF54F registered?
Mode-S code ACF54F 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 ACF54F broadcasting right now?
Yes. Mode-S ACF54F is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACF54F, octal 53172517, decimal 11,334,991.
What flights does ACF54F operate?
Mode-S ACF54F has broadcast 4 distinct callsigns, including JBU934, JBU933, JBU387, JBU900.