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
Broadcasting now · callsign JAL432 · 17,375 ft
Flights observed
11
Distinct callsigns
8
Country
JP
Last broadcast
16h ago

Current position

851BFE is currently broadcasting. Map zoomed to live position.

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 8 distinct

Callsign Airline Flights Last seen
JAL665 Japan Airlines 3 2026-04-13
JAL586 - 2 2026-04-14
JAL670 - 1 2026-04-13
JAL562 - 1 2026-04-13
JAL545 - 1 2026-04-14
JAL498 - 1 2026-04-13
JAL497 - 1 2026-04-13
JAL373 Japan Airlines 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 JAL545 - Apr 14, 08:30 UTCApr 14, 08:55 UTC25m
2026-04-14 JAL586 - Apr 14, 07:10 UTCApr 14, 07:20 UTC10m
2026-04-14 JAL586 - Apr 14, 06:10 UTCApr 14, 07:10 UTC1h 0m
2026-04-13 JAL373 HND → KKJ Apr 13, 23:15 UTCApr 13, 23:40 UTC25m
2026-04-13 JAL498 - Apr 13, 11:00 UTCApr 13, 11:40 UTC40m
2026-04-13 JAL497 - Apr 13, 08:35 UTCApr 13, 09:05 UTC30m
2026-04-13 JAL670 - Apr 13, 06:00 UTCApr 13, 07:10 UTC1h 10m
2026-04-13 JAL665 HND → OIT Apr 13, 04:20 UTCApr 13, 04:40 UTC20m
2026-04-13 JAL665 HND → OIT Apr 13, 03:55 UTCApr 13, 04:40 UTC45m
2026-04-13 JAL665 HND → OIT Apr 13, 03:40 UTCApr 13, 04:15 UTC35m
2026-04-13 JAL562 - Apr 13, 00:25 UTCApr 13, 02:15 UTC1h 50m

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?
Yes. Mode-S 851BFE is currently airborne.
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 8 distinct callsigns, including JAL665, JAL586, JAL670, JAL562, JAL545.