sensors Mode-S transponder

861F66

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA618J · BOEING 767-300

Hex
861F66
Octal
41417546
Decimal
8,789,862
Country
JP
Tail
JA618J
Type
B763
Broadcasting now · callsign JAL117 · 26,000 ft
Flights observed
6
Distinct callsigns
5
Country
JP
Last broadcast
19h ago

Current position

861F66 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 861F66 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 5 distinct

Callsign Airline Flights Last seen
JAL8663 Japan Airlines 2 2026-04-13
JAL8664 - 1 2026-04-13
JAL651 Japan Airlines 1 2026-04-14
JAL4123 - 1 2026-04-13
JAL120 - 1 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 JAL651 HND → KOJ Apr 14, 07:50 UTCApr 14, 08:35 UTC45m
2026-04-14 JAL120 - Apr 14, 05:40 UTCApr 14, 06:30 UTC50m
2026-04-13 JAL4123 - Apr 13, 13:00 UTCApr 13, 13:20 UTC20m
2026-04-13 JAL8664 - Apr 13, 05:00 UTCApr 13, 07:40 UTC2h 40m
2026-04-13 JAL8663 NRT → TPE Apr 13, 03:20 UTCApr 13, 03:40 UTC20m
2026-04-13 JAL8663 NRT → TPE Apr 13, 00:25 UTCApr 13, 01:30 UTC1h 5m

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 JA618J page for operator, model, and routing details .

Mode-S 861F66 frequently asked

What is Mode-S code 861F66?
861F66 is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA618J.
Where is Mode-S 861F66 registered?
Mode-S code 861F66 is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 861F66 broadcasting right now?
Yes. Mode-S 861F66 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 861F66, octal 41417546, decimal 8,789,862.
What flights does 861F66 operate?
Mode-S 861F66 has broadcast 5 distinct callsigns, including JAL8663, JAL8664, JAL651, JAL4123, JAL120.