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
- Flights observed
- 252
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- Jul 26, 18:20 UTC
Last known position
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 | JetBlue Airways | 26 | 2026-07-24 |
| JBU346 | JetBlue Airways | 22 | 2026-07-24 |
| JBU32 | - | 15 | 2026-07-09 |
| JBU31 | - | 14 | 2026-07-09 |
| JBU1620 | JetBlue Airways | 14 | 2026-07-19 |
| JBU33 | JetBlue Airways | 12 | 2026-07-26 |
| JBU1408 | JetBlue Airways | 12 | 2026-06-19 |
| JBU7 | - | 11 | 2026-06-20 |
| JBU331 | JetBlue Airways | 11 | 2026-07-24 |
| 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 |
| JBU332 | JetBlue Airways | 9 | 2026-07-25 |
| 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 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-26 | JBU33 | BOS → SFO | Jul 26, 01:26 UTC | Jul 26, 18:20 UTC | 16h 55m |
| 2026-07-25 | JBU332 | LGA → BOS | Jul 25, 08:35 UTC | Jul 25, 10:00 UTC | 1h 25m |
| 2026-07-25 | JBU332 | LGA → BOS | Jul 25, 08:35 UTC | Jul 26, 07:55 UTC | 23h 21m |
| 2026-07-24 | JBU331 | BDL → MCO | Jul 24, 23:05 UTC | Jul 25, 06:15 UTC | 7h 10m |
| 2026-07-24 | JBU346 | SRQ → JFK | Jul 24, 11:30 UTC | Jul 24, 19:15 UTC | 7h 45m |
| 2026-07-24 | JBU345 | JFK → SRQ | Jul 24, 00:50 UTC | Jul 24, 07:45 UTC | 6h 55m |
| 2026-07-22 | JBU331 | BDL → MCO | Jul 22, 22:37 UTC | Jul 23, 16:40 UTC | 18h 3m |
| 2026-07-22 | JBU346 | SRQ → JFK | Jul 22, 11:15 UTC | Jul 22, 19:00 UTC | 7h 45m |
| 2026-07-22 | JBU346 | SRQ → JFK | Jul 22, 11:11 UTC | Jul 23, 10:00 UTC | 22h 49m |
| 2026-07-22 | JBU345 | JFK → SRQ | Jul 22, 01:29 UTC | Jul 22, 02:50 UTC | 1h 21m |
| 2026-07-22 | JBU345 | JFK → SRQ | Jul 22, 01:30 UTC | Jul 22, 02:00 UTC | 30m |
| 2026-07-20 | JBU331 | BDL → MCO | Jul 20, 22:50 UTC | Jul 21, 06:00 UTC | 7h 10m |
| 2026-07-20 | JBU331 | BDL → MCO | Jul 20, 22:48 UTC | Jul 21, 16:30 UTC | 17h 42m |
| 2026-07-19 | JBU1620 | BOS → LHR | Jul 19, 23:05 UTC | Jul 20, 15:10 UTC | 16h 6m |
| 2026-07-19 | JBU332 | LGA → BOS | Jul 19, 09:05 UTC | Jul 19, 11:10 UTC | 2h 5m |
| 2026-07-19 | JBU332 | LGA → BOS | Jul 19, 09:04 UTC | Jul 20, 05:25 UTC | 20h 22m |
| 2026-07-19 | JBU332 | LGA → BOS | Jul 19, 09:04 UTC | Jul 20, 05:25 UTC | 20h 22m |
| 2026-07-18 | JBU331 | BDL → MCO | Jul 18, 23:25 UTC | Jul 19, 06:55 UTC | 7h 30m |
| 2026-07-18 | JBU346 | BCN → BOS | Jul 18, 11:07 UTC | Jul 19, 10:00 UTC | 22h 54m |
| 2026-07-18 | JBU346 | BCN → BOS | Jul 18, 11:10 UTC | Jul 18, 19:40 UTC | 8h 30m |
| 2026-07-18 | JBU345 | - | Jul 18, 00:50 UTC | Jul 18, 07:45 UTC | 6h 56m |
| 2026-07-18 | JBU345 | BOS → BOS | Jul 18, 00:29 UTC | Jul 18, 00:35 UTC | 5m |
| 2026-07-17 | JBU345 | BOS → BCN | Jul 17, 00:56 UTC | Jul 17, 19:40 UTC | 18h 44m |
| 2026-07-16 | JBU346 | BCN → BOS | Jul 16, 11:50 UTC | Jul 17, 08:04 UTC | 20h 15m |
| 2026-07-16 | JBU345 | BOS → BCN | Jul 16, 01:08 UTC | Jul 16, 23:55 UTC | 22h 47m |
| 2026-07-16 | JBU345 | BOS → BCN | Jul 16, 01:10 UTC | Jul 16, 08:05 UTC | 6h 55m |
| 2026-07-15 | JBU332 | MXP → BOS | Jul 15, 09:20 UTC | Jul 15, 17:25 UTC | 8h 5m |
| 2026-07-14 | JBU331 | BOS → MXP | Jul 14, 22:50 UTC | Jul 15, 06:15 UTC | 7h 25m |
| 2026-07-14 | JBU346 | BCN → BOS | Jul 14, 11:16 UTC | Jul 15, 10:00 UTC | 22h 44m |
| 2026-07-14 | JBU346 | - | Jul 14, 11:20 UTC | Jul 14, 12:00 UTC | 40m |
| 2026-07-14 | JBU345 | BOS → BCN | Jul 14, 00:50 UTC | Jul 14, 07:40 UTC | 6h 50m |
| 2026-07-13 | JBU332 | - | Jul 13, 09:00 UTC | Jul 13, 11:35 UTC | 2h 35m |
| 2026-07-13 | JBU332 | MXP → BOS | Jul 13, 09:00 UTC | Jul 14, 07:45 UTC | 22h 46m |
| 2026-07-12 | JBU331 | - | Jul 12, 22:35 UTC | Jul 13, 05:55 UTC | 7h 20m |
| 2026-07-12 | JBU346 | BCN → BOS | Jul 12, 11:25 UTC | Jul 12, 19:05 UTC | 7h 40m |
| 2026-07-12 | JBU345 | BOS → BCN | Jul 12, 00:55 UTC | Jul 12, 07:55 UTC | 7h 0m |
| 2026-07-11 | JBU332 | MXP → BOS | Jul 11, 09:50 UTC | Jul 11, 18:00 UTC | 8h 10m |
| 2026-07-10 | JBU331 | BOS → MXP | Jul 10, 23:20 UTC | Jul 11, 06:35 UTC | 7h 15m |
| 2026-07-10 | JBU345 | BOS → BCN | Jul 10, 01:13 UTC | Jul 11, 00:00 UTC | 22h 48m |
| 2026-07-10 | JBU345 | BOS → BCN | Jul 10, 01:15 UTC | Jul 10, 08:20 UTC | 7h 5m |
| 2026-07-09 | JBU32 | - | Jul 9, 10:00 UTC | Jul 9, 17:15 UTC | 7h 15m |
| 2026-07-09 | JBU31 | - | Jul 9, 00:30 UTC | Jul 9, 07:05 UTC | 6h 35m |
| 2026-07-08 | JBU346 | BCN → BOS | Jul 8, 11:21 UTC | Jul 9, 10:00 UTC | 22h 40m |
| 2026-07-08 | JBU345 | BOS → BCN | Jul 8, 00:45 UTC | Jul 8, 19:30 UTC | 18h 46m |
| 2026-07-08 | JBU345 | - | Jul 8, 00:45 UTC | Jul 8, 01:40 UTC | 55m |
| 2026-07-07 | JBU32 | AMS → BOS | Jul 7, 09:30 UTC | Jul 7, 17:25 UTC | 7h 55m |
| 2026-07-06 | JBU346 | BCN → BOS | Jul 6, 14:01 UTC | Jul 7, 11:10 UTC | 21h 10m |
| 2026-07-06 | JBU346 | BCN → BOS | Jul 6, 14:01 UTC | Jul 7, 11:10 UTC | 21h 10m |
| 2026-07-06 | JBU345 | BOS → BCN | Jul 6, 04:20 UTC | Jul 6, 11:10 UTC | 6h 50m |
| 2026-07-06 | JBU345 | BOS → BCN | Jul 6, 04:18 UTC | Jul 7, 02:20 UTC | 22h 3m |
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 .