Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A4C9F8

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N4077J · AIRBUS A-321neo · operated by JETBLUE AIRWAYS CORP

Hex
A4C9F8
Octal
51144770
Decimal
10,799,608
Country
US
Tail
N4077J
Type
A21N
Transponder active on ground
Flights observed
222
Distinct callsigns
20
Country
US
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S A4C9F8.

Country allocation

The ICAO 24-bit address A4C9F8 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 20 distinct

Callsign Airline Flights Last seen
JBU345 - 18 2026-07-14
JBU32 - 15 2026-07-09
JBU346 - 14 2026-07-12
JBU31 - 14 2026-07-09
JBU1620 - 13 2026-07-01
JBU1408 JetBlue Airways 12 2026-06-19
JBU7 - 11 2026-06-20
JBU33 - 11 2026-06-19
JBU2261 - 11 2026-07-04
JBU20 JetBlue Airways 11 2026-06-12
JBU1107 JetBlue Airways 11 2026-06-22
JBU34 - 10 2026-06-24
JBU2260 - 10 2026-07-04
JBU2220 JetBlue Airways 8 2026-06-23
JBU1621 - 8 2026-07-02
JBU1407 JetBlue Airways 7 2026-06-24
JBU323 JetBlue Airways 6 2026-04-15
JBU2124 JetBlue Airways 6 2026-04-16
JBU331 - 5 2026-07-12
JBU842 JetBlue Airways 3 2026-06-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 JBU345 BOS → BCN Jul 14, 00:50 UTCJul 14, 07:40 UTC6h 50m
2026-07-13 JBU332 - Jul 13, 09:00 UTCJul 13, 11:35 UTC2h 35m
2026-07-13 JBU332 MXP → BOS Jul 13, 09:00 UTCJul 14, 07:45 UTC22h 46m
2026-07-12 JBU331 - Jul 12, 22:35 UTCJul 13, 05:55 UTC7h 20m
2026-07-12 JBU346 BCN → BOS Jul 12, 11:25 UTCJul 12, 19:05 UTC7h 40m
2026-07-12 JBU345 BOS → BCN Jul 12, 00:55 UTCJul 12, 07:55 UTC7h 0m
2026-07-11 JBU332 MXP → BOS Jul 11, 09:50 UTCJul 11, 18:00 UTC8h 10m
2026-07-10 JBU331 BOS → MXP Jul 10, 23:20 UTCJul 11, 06:35 UTC7h 15m
2026-07-10 JBU345 BOS → BCN Jul 10, 01:13 UTCJul 11, 00:00 UTC22h 48m
2026-07-10 JBU345 BOS → BCN Jul 10, 01:15 UTCJul 10, 08:20 UTC7h 5m
2026-07-09 JBU32 - Jul 9, 10:00 UTCJul 9, 17:15 UTC7h 15m
2026-07-09 JBU31 - Jul 9, 00:30 UTCJul 9, 07:05 UTC6h 35m
2026-07-08 JBU346 BCN → BOS Jul 8, 11:21 UTCJul 9, 10:00 UTC22h 40m
2026-07-08 JBU345 BOS → BCN Jul 8, 00:45 UTCJul 8, 19:30 UTC18h 46m
2026-07-08 JBU345 - Jul 8, 00:45 UTCJul 8, 01:40 UTC55m
2026-07-07 JBU32 AMS → BOS Jul 7, 09:30 UTCJul 7, 17:25 UTC7h 55m
2026-07-06 JBU346 BCN → BOS Jul 6, 14:01 UTCJul 7, 11:10 UTC21h 10m
2026-07-06 JBU346 BCN → BOS Jul 6, 14:01 UTCJul 7, 11:10 UTC21h 10m
2026-07-06 JBU345 BOS → BCN Jul 6, 04:20 UTCJul 6, 11:10 UTC6h 50m
2026-07-06 JBU345 BOS → BCN Jul 6, 04:18 UTCJul 7, 02:20 UTC22h 3m
2026-07-05 JBU32 AMS → BOS Jul 5, 09:46 UTCJul 6, 05:35 UTC19h 50m
2026-07-05 JBU32 AMS → BOS Jul 5, 09:46 UTCJul 6, 05:35 UTC19h 50m
2026-07-04 JBU2260 MAD → BOS Jul 4, 12:32 UTCJul 5, 11:35 UTC23h 3m
2026-07-04 JBU2260 - Jul 4, 12:35 UTCJul 4, 19:50 UTC7h 15m
2026-07-04 JBU2261 - Jul 4, 03:00 UTCJul 4, 09:40 UTC6h 40m
2026-07-04 JBU2261 BOS → BOS Jul 4, 02:20 UTCJul 4, 02:25 UTC5m
2026-07-04 JBU2261 BOS → BOS Jul 4, 02:00 UTCJul 4, 02:05 UTC5m
2026-07-04 JBU2261 BOS → BOS Jul 4, 01:30 UTCJul 4, 01:55 UTC25m
2026-07-02 JBU1621 - Jul 2, 07:55 UTCJul 2, 15:25 UTC7h 30m
2026-07-01 JBU1620 - Jul 1, 23:40 UTCJul 2, 05:15 UTC5h 35m
2026-07-01 JBU1620 - Jul 1, 22:55 UTCJul 1, 23:35 UTC40m
2026-06-30 JBU8353 - Jun 30, 09:15 UTCJun 30, 11:45 UTC2h 30m
2026-06-30 JBU8353 MXP → BOS Jun 30, 09:10 UTCJun 30, 17:30 UTC8h 21m
2026-06-29 JBU331 BDL → MCO Jun 29, 00:34 UTCJun 29, 07:25 UTC6h 50m
2026-06-28 JBU1621 - Jun 28, 09:20 UTCJun 28, 16:25 UTC7h 5m
2026-06-28 JBU1621 LHR → BOS Jun 28, 09:16 UTCJun 29, 07:30 UTC22h 14m
2026-06-27 JBU346 BCN → BOS Jun 27, 11:20 UTCJun 28, 10:00 UTC22h 40m
2026-06-27 JBU345 - Jun 27, 01:24 UTCJun 27, 07:49 UTC6h 25m
2026-06-27 JBU345 BOS → BCN Jun 27, 01:21 UTCJun 28, 00:00 UTC22h 39m
2026-06-27 JBU345 BOS → BOS Jun 27, 00:20 UTCJun 27, 00:25 UTC5m
2026-06-26 JBU32 AMS → BOS Jun 26, 09:35 UTCJun 26, 16:54 UTC7h 20m
2026-06-26 JBU31 BOS → AMS Jun 26, 00:45 UTCJun 26, 07:00 UTC6h 15m
2026-06-25 JBU31 BOS → AMS Jun 25, 00:28 UTCJun 25, 23:59 UTC23h 32m
2026-06-25 JBU31 BOS → AMS Jun 25, 00:29 UTCJun 25, 06:44 UTC6h 15m
2026-06-24 JBU34 - Jun 24, 09:39 UTCJun 24, 17:29 UTC7h 50m
2026-06-24 JBU1407 JFK → CDG Jun 24, 00:30 UTCJun 24, 07:15 UTC6h 45m
2026-06-23 JBU2220 LHR → JFK Jun 23, 08:04 UTCJun 23, 15:50 UTC7h 45m
2026-06-22 JBU1107 JFK → LHR Jun 22, 13:14 UTCJun 22, 19:29 UTC6h 15m
2026-06-22 JBU1524 LAX → JFK Jun 22, 04:09 UTCJun 22, 09:04 UTC4h 55m
2026-06-21 JBU842 DUB → JFK Jun 21, 10:54 UTCJun 21, 17:50 UTC6h 55m

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 N4077J page for operator, model, and routing details .

Mode-S A4C9F8 frequently asked

What is Mode-S code A4C9F8?
A4C9F8 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N4077J.
Where is Mode-S A4C9F8 registered?
Mode-S code A4C9F8 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 A4C9F8 broadcasting right now?
Mode-S A4C9F8 is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4C9F8, octal 51144770, decimal 10,799,608.
What flights does A4C9F8 operate?
Mode-S A4C9F8 has broadcast 20 distinct callsigns, including JBU345, JBU32, JBU346, JBU31, JBU1620.