sensors Mode-S transponder
A38439
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N3257J · operated by JETBLUE AIRWAYS CORP
- Hex
- A38439
- Octal
- 50702071
- Decimal
- 10,716,217
- Country
- US
- Tail
- N3257J
- Type
- BCS3
- Flights observed
- 314
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- Jul 26, 22:15 UTC
Last known position
Country allocation
The ICAO 24-bit address A38439 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 |
|---|---|---|---|
| JBU855 | JetBlue Airways | 5 | 2026-06-12 |
| JBU2468 | - | 5 | 2026-06-19 |
| JBU2321 | - | 5 | 2026-07-10 |
| JBU896 | JetBlue Airways | 4 | 2026-06-10 |
| JBU811 | JetBlue Airways | 4 | 2026-05-01 |
| JBU715 | JetBlue Airways | 4 | 2026-05-19 |
| JBU521 | JetBlue Airways | 4 | 2026-07-21 |
| JBU266 | - | 4 | 2026-07-02 |
| JBU1855 | JetBlue Airways | 4 | 2026-04-28 |
| JBU1355 | JetBlue Airways | 4 | 2026-06-07 |
| JBU1310 | JetBlue Airways | 4 | 2026-07-24 |
| JBU1303 | JetBlue Airways | 4 | 2026-04-15 |
| JBU97 | - | 3 | 2026-07-14 |
| JBU818 | - | 3 | 2026-07-09 |
| JBU641 | JetBlue Airways | 3 | 2026-05-14 |
| JBU639 | JetBlue Airways | 3 | 2026-07-24 |
| JBU502 | JetBlue Airways | 3 | 2026-04-16 |
| JBU401 | - | 3 | 2026-04-13 |
| JBU400 | JetBlue Airways | 3 | 2026-04-13 |
| JBU2768 | - | 3 | 2026-07-09 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-26 | JBU1955 | BOS → DCA | Jul 26, 21:40 UTC | Jul 26, 22:15 UTC | 35m |
| 2026-07-26 | JBU1232 | LGA → BOS | Jul 26, 16:55 UTC | Jul 26, 19:30 UTC | 2h 35m |
| 2026-07-26 | JBU1231 | BOS → LGA | Jul 26, 12:50 UTC | Jul 26, 15:25 UTC | 2h 35m |
| 2026-07-25 | JBU1238 | AUS → BOS | Jul 25, 15:23 UTC | Jul 26, 14:15 UTC | 22h 53m |
| 2026-07-25 | JBU1439 | BOS → AUS | Jul 25, 10:03 UTC | Jul 26, 05:40 UTC | 19h 37m |
| 2026-07-24 | JBU639 | BOS → MIA | Jul 24, 18:50 UTC | Jul 24, 22:35 UTC | 3h 45m |
| 2026-07-24 | JBU639 | BOS → MIA | Jul 24, 18:47 UTC | Jul 25, 18:15 UTC | 23h 28m |
| 2026-07-24 | JBU1310 | JAX → BOS | Jul 24, 15:00 UTC | Jul 24, 17:10 UTC | 2h 10m |
| 2026-07-24 | JBU109 | BOS → JAX | Jul 24, 11:20 UTC | Jul 24, 13:40 UTC | 2h 20m |
| 2026-07-23 | JBU22 | MBJ → MCO | Jul 23, 21:45 UTC | Jul 24, 00:15 UTC | 2h 30m |
| 2026-07-23 | JBU53 | JFK → PBI | Jul 23, 17:50 UTC | Jul 23, 20:20 UTC | 2h 30m |
| 2026-07-23 | JBU2786 | RDU → JFK | Jul 23, 15:20 UTC | Jul 23, 16:25 UTC | 1h 5m |
| 2026-07-23 | JBU2285 | JFK → RDU | Jul 23, 12:55 UTC | Jul 23, 14:10 UTC | 1h 15m |
| 2026-07-22 | JBU184 | RDU → BOS | Jul 22, 16:39 UTC | Jul 23, 16:15 UTC | 23h 36m |
| 2026-07-22 | JBU338 | MCO → IAD | Jul 22, 01:12 UTC | Jul 22, 18:55 UTC | 17h 43m |
| 2026-07-21 | JBU521 | BOS → JFK | Jul 21, 18:11 UTC | Jul 22, 14:45 UTC | 20h 34m |
| 2026-07-21 | JBU521 | BOS → JFK | Jul 21, 18:15 UTC | Jul 21, 22:15 UTC | 4h 0m |
| 2026-07-21 | JBU1406 | SDQ → MCO | Jul 21, 09:25 UTC | Jul 21, 15:45 UTC | 6h 20m |
| 2026-07-19 | JBU737 | BDL → MCO | Jul 19, 11:21 UTC | Jul 19, 19:45 UTC | 8h 25m |
| 2026-07-18 | JBU521 | BOS → JFK | Jul 18, 18:15 UTC | Jul 18, 19:05 UTC | 50m |
| 2026-07-18 | JBU521 | BOS → JFK | Jul 18, 18:11 UTC | Jul 19, 13:55 UTC | 19h 45m |
| 2026-07-18 | JBU1406 | MCO → MCO | Jul 18, 09:20 UTC | Jul 18, 15:20 UTC | 6h 0m |
| 2026-07-18 | JBU1083 | JFK → MCO | Jul 18, 01:20 UTC | Jul 18, 03:25 UTC | 2h 6m |
| 2026-07-17 | JBU678 | JAX → JFK | Jul 17, 21:50 UTC | Jul 17, 23:50 UTC | 2h 0m |
| 2026-07-17 | JBU677 | - | Jul 17, 18:25 UTC | Jul 17, 20:20 UTC | 1h 55m |
| 2026-07-17 | JBU1520 | ATL → JFK | Jul 17, 14:35 UTC | Jul 17, 16:24 UTC | 1h 50m |
| 2026-07-17 | JBU519 | JFK → ATL | Jul 17, 11:20 UTC | Jul 17, 13:00 UTC | 1h 40m |
| 2026-07-17 | JBU1274 | - | Jul 17, 00:35 UTC | Jul 17, 02:15 UTC | 1h 40m |
| 2026-07-16 | JBU2473 | - | Jul 16, 21:55 UTC | Jul 16, 23:29 UTC | 1h 35m |
| 2026-07-15 | JBU820 | JFK → DTW | Jul 15, 03:34 UTC | Jul 15, 18:55 UTC | 15h 21m |
| 2026-07-14 | JBU1737 | JFK → STI | Jul 14, 11:41 UTC | Jul 15, 10:15 UTC | 22h 34m |
| 2026-07-14 | JBU98 | - | Jul 14, 06:10 UTC | Jul 14, 06:15 UTC | 5m |
| 2026-07-14 | JBU97 | JFK → DEN | Jul 14, 01:20 UTC | Jul 14, 04:35 UTC | 3h 15m |
| 2026-07-14 | JBU97 | JFK → DEN | Jul 14, 01:20 UTC | Jul 14, 23:40 UTC | 22h 20m |
| 2026-07-13 | JBU1498 | DEN → JFK | Jul 13, 20:25 UTC | Jul 14, 00:00 UTC | 3h 35m |
| 2026-07-13 | JBU1497 | JFK → DEN | Jul 13, 14:40 UTC | Jul 13, 18:05 UTC | 3h 25m |
| 2026-07-12 | JBU341 | JFK → SAV | Jul 12, 21:11 UTC | Jul 13, 20:15 UTC | 23h 5m |
| 2026-07-12 | JBU341 | - | Jul 12, 21:15 UTC | Jul 12, 22:15 UTC | 1h 0m |
| 2026-07-11 | JBU2291 | JFK → ACK | Jul 11, 18:27 UTC | Jul 12, 11:25 UTC | 16h 59m |
| 2026-07-11 | JBU2291 | - | Jul 11, 18:30 UTC | Jul 11, 19:00 UTC | 30m |
| 2026-07-11 | JBU142 | SAV → JFK | Jul 11, 15:25 UTC | Jul 11, 17:00 UTC | 1h 35m |
| 2026-07-11 | JBU249 | BOS → SAV | Jul 11, 11:50 UTC | Jul 11, 13:50 UTC | 2h 0m |
| 2026-07-11 | JBU2322 | - | Jul 11, 00:45 UTC | Jul 11, 03:25 UTC | 2h 40m |
| 2026-07-10 | JBU2321 | - | Jul 10, 20:50 UTC | Jul 10, 23:40 UTC | 2h 50m |
| 2026-07-10 | JBU392 | TPA → BOS | Jul 10, 16:45 UTC | Jul 10, 19:25 UTC | 2h 40m |
| 2026-07-09 | JBU818 | JFK → BOS | Jul 9, 23:52 UTC | Jul 10, 21:55 UTC | 22h 4m |
| 2026-07-09 | JBU176 | MSY → JFK | Jul 9, 19:30 UTC | Jul 10, 18:15 UTC | 22h 46m |
| 2026-07-09 | JBU2769 | CLE → JFK | Jul 9, 10:30 UTC | Jul 10, 10:15 UTC | 23h 45m |
| 2026-07-09 | JBU2768 | JFK → CLE | Jul 9, 01:53 UTC | Jul 10, 00:15 UTC | 22h 23m |
| 2026-07-09 | JBU2768 | - | Jul 9, 01:55 UTC | Jul 9, 03:05 UTC | 1h 10m |
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 N3257J page for operator, model, and routing details .