Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

851BFE

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA342J · BOEING 737-800

Hex
851BFE
Octal
41215776
Decimal
8,723,454
Country
JP
Tail
JA342J
Type
B738
No current signal · last broadcast Jul 26, 12:30 UTC
Flights observed
626
Distinct callsigns
20
Country
JP
Last broadcast
Jul 26, 12:30 UTC

Last known position

Most recent position reported by Mode-S 851BFE.

Country allocation

The ICAO 24-bit address 851BFE falls within the block assigned to Japan (JP) by ICAO Annex 10, Volume III. Every aircraft registered in Japan 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
JAL665 Japan Airlines 7 2026-07-23
JAL545 Japan Airlines 7 2026-07-21
JAL674 - 6 2026-07-22
JAL544 - 6 2026-07-21
JAL487 Japan Airlines 6 2026-07-24
JAL478 Japan Airlines 6 2026-07-25
JAL477 Japan Airlines 6 2026-07-25
JAL474 Japan Airlines 6 2026-07-24
JAL435 Japan Airlines 6 2026-07-22
JAL3512 Japan Airlines 6 2026-07-24
JAL3510 - 6 2026-06-14
JAL3403 Japan Airlines 6 2026-07-24
JAL324 Japan Airlines 6 2026-07-24
JAL255 Japan Airlines 6 2026-07-24
JAL234 Japan Airlines 6 2026-07-22
JAL231 - 6 2026-07-21
JAL229 Japan Airlines 6 2026-07-23
JAL220 Japan Airlines 6 2026-07-23
JAL146 Japan Airlines 6 2026-07-21
JAL145 Japan Airlines 6 2026-07-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 JAL134 ITM → HND Jul 26, 11:40 UTCJul 26, 12:20 UTC40m
2026-07-26 JL131 HND → ITM Jul 26, 09:50 UTCJul 26, 10:35 UTC45m
2026-07-26 JAL659 HND → ASJ Jul 26, 03:05 UTCJul 26, 08:15 UTC5h 11m
2026-07-26 JAL212 SHM → HND Jul 26, 01:05 UTCJul 26, 01:45 UTC40m
2026-07-25 JAL213 HND → SHM Jul 25, 23:10 UTCJul 25, 23:40 UTC30m
2026-07-25 JL266 HIJ → HND Jul 25, 13:20 UTCJul 25, 14:20 UTC1h 0m
2026-07-25 JAL265 HND → HIJ Jul 25, 11:25 UTCJul 25, 12:30 UTC1h 5m
2026-07-25 JAL376 KKJ → HND Jul 25, 08:50 UTCJul 25, 10:00 UTC1h 10m
2026-07-25 JAL375 HND → KKJ Jul 25, 06:30 UTCJul 25, 07:35 UTC1h 5m
2026-07-25 JAL478 TAK → HND Jul 25, 02:45 UTCJul 25, 03:45 UTC1h 0m
2026-07-25 JAL477 HND → TAK Jul 25, 01:00 UTCJul 25, 01:50 UTC50m
2026-07-24 JAL474 TAK → HND Jul 24, 22:15 UTCJul 24, 23:10 UTC55m
2026-07-24 JAL487 HND → TAK Jul 24, 11:55 UTCJul 24, 12:40 UTC45m
2026-07-24 JAL324 FUK → HND Jul 24, 09:10 UTCJul 24, 10:45 UTC1h 35m
2026-07-24 JAL3512 CTS → FUK Jul 24, 04:55 UTCJul 24, 07:00 UTC2h 5m
2026-07-24 JAL3403 HIJ → CTS Jul 24, 02:00 UTCJul 24, 03:50 UTC1h 50m
2026-07-24 JAL255 HND → HIJ Jul 24, 00:10 UTCJul 24, 01:10 UTC1h 0m
2026-07-23 JAL220 KIX → HND Jul 23, 22:00 UTCJul 23, 22:50 UTC50m
2026-07-23 JAL229 HND → KIX Jul 23, 12:25 UTCJul 23, 13:10 UTC45m
2026-07-23 JAL498 - Jul 23, 10:30 UTCJul 23, 11:20 UTC50m
2026-07-23 JAL497 HND → KCZ Jul 23, 08:25 UTCJul 23, 09:05 UTC40m
2026-07-23 JAL670 OIT → HND Jul 23, 05:50 UTCJul 23, 07:05 UTC1h 15m
2026-07-23 JAL665 HND → OIT Jul 23, 03:40 UTCJul 23, 04:40 UTC1h 0m
2026-07-23 JAL562 MMB → HND Jul 23, 00:40 UTCJul 23, 02:10 UTC1h 30m
2026-07-22 JAL565 HND → MMB Jul 22, 22:15 UTCJul 22, 23:40 UTC1h 25m
2026-07-22 JAL674 - Jul 22, 11:10 UTCJul 22, 11:40 UTC30m
2026-07-22 JAL435 HND → MYJ Jul 22, 03:25 UTCJul 22, 04:25 UTC1h 0m
2026-07-22 JAL234 OKJ → HND Jul 22, 01:15 UTCJul 22, 02:20 UTC1h 5m
2026-07-21 JAL231 - Jul 21, 23:30 UTCJul 22, 00:20 UTC50m
2026-07-21 JAL544 - Jul 21, 11:20 UTCJul 21, 12:30 UTC1h 10m
2026-07-21 JAL545 HND → KUH Jul 21, 09:00 UTCJul 21, 10:05 UTC1h 5m
2026-07-21 JAL146 AOJ → HND Jul 21, 06:35 UTCJul 21, 07:35 UTC1h 0m
2026-07-21 JAL145 HND → AOJ Jul 21, 04:45 UTCJul 21, 05:40 UTC55m
2026-07-21 JAL374 KKJ → HND Jul 21, 01:50 UTCJul 21, 03:00 UTC1h 10m
2026-07-20 JAL373C - Jul 20, 23:35 UTCJul 21, 00:35 UTC1h 0m
2026-07-20 JAL544 - Jul 20, 11:15 UTCJul 20, 12:30 UTC1h 15m
2026-07-20 JAL545 HND → KUH Jul 20, 08:55 UTCJul 20, 10:00 UTC1h 5m
2026-07-20 JAL146 AOJ → HND Jul 20, 06:30 UTCJul 20, 07:30 UTC1h 0m
2026-07-20 JAL145 HND → AOJ Jul 20, 04:35 UTCJul 20, 05:25 UTC50m
2026-07-20 JAL374 KKJ → HND Jul 20, 01:45 UTCJul 20, 03:00 UTC1h 15m
2026-07-19 JAL373C - Jul 19, 23:35 UTCJul 20, 00:35 UTC1h 0m
2026-07-19 JAL566 - Jul 19, 11:00 UTCJul 19, 12:25 UTC1h 25m
2026-07-19 JAL569 HND → MMB Jul 19, 08:30 UTCJul 19, 10:00 UTC1h 30m
2026-07-19 JAL542 KUH → HND Jul 19, 06:05 UTCJul 19, 07:15 UTC1h 10m
2026-07-19 JAL543 - Jul 19, 03:35 UTCJul 19, 04:40 UTC1h 5m
2026-07-19 JAL112 - Jul 19, 01:30 UTCJul 19, 02:25 UTC55m
2026-07-18 JAL107 HND → ITM Jul 18, 23:50 UTCJul 19, 00:30 UTC40m
2026-07-18 JAL652 - Jul 18, 10:35 UTCJul 18, 11:45 UTC1h 10m
2026-07-18 JAL651 HND → KOJ Jul 18, 08:00 UTCJul 18, 09:00 UTC1h 0m
2026-07-18 JAL118 - Jul 18, 04:40 UTCJul 18, 05:35 UTC55m

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 JA342J page for operator, model, and routing details .

Mode-S 851BFE frequently asked

What is Mode-S code 851BFE?
851BFE is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA342J.
Where is Mode-S 851BFE registered?
Mode-S code 851BFE is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 851BFE broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 12:30 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 851BFE, octal 41215776, decimal 8,723,454.
What flights does 851BFE operate?
Mode-S 851BFE has broadcast 20 distinct callsigns, including JAL665, JAL545, JAL674, JAL544, JAL487.