sensors Mode-S transponder

8681A8

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA73NA · BOEING 737-800

Hex
8681A8
Octal
41500650
Decimal
8,815,016
Country
JP
Tail
JA73NA
Type
B738
No current signal · last broadcast 15h ago
Flights observed
10
Distinct callsigns
8
Country
JP
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S 8681A8.

Country allocation

The ICAO 24-bit address 8681A8 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
SKY706 - 2 2026-04-13
SKY117 - 2 2026-04-13
SKY509 Skymark Airlines 1 2026-04-14
SKY508 - 1 2026-04-14
SKY506 - 1 2026-04-14
SKY152 - 1 2026-04-13
SKY020 - 1 2026-04-13
SKY019 Skymark Airlines 1 2026-04-13

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-14 SKY508 - Apr 14, 10:55 UTCApr 14, 11:05 UTC10m
2026-04-14 SKY509 FUK → OKA Apr 14, 09:25 UTCApr 14, 09:50 UTC25m
2026-04-14 SKY506 - Apr 14, 05:55 UTCApr 14, 06:15 UTC20m
2026-04-13 SKY152 - Apr 13, 22:55 UTCApr 13, 23:40 UTC45m
2026-04-13 SKY117 - Apr 13, 11:55 UTCApr 13, 12:05 UTC10m
2026-04-13 SKY117 - Apr 13, 11:20 UTCApr 13, 12:05 UTC45m
2026-04-13 SKY020 - Apr 13, 09:00 UTCApr 13, 10:20 UTC1h 20m
2026-04-13 SKY019 HND → FUK Apr 13, 06:20 UTCApr 13, 07:35 UTC1h 15m
2026-04-13 SKY706 - Apr 13, 00:20 UTCApr 13, 00:50 UTC30m
2026-04-12 SKY706 - Apr 12, 23:55 UTCApr 13, 00:50 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 JA73NA page for operator, model, and routing details .

Mode-S 8681A8 frequently asked

What is Mode-S code 8681A8?
8681A8 is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA73NA.
Where is Mode-S 8681A8 registered?
Mode-S code 8681A8 is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8681A8 broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8681A8, octal 41500650, decimal 8,815,016.
What flights does 8681A8 operate?
Mode-S 8681A8 has broadcast 8 distinct callsigns, including SKY706, SKY117, SKY509, SKY508, SKY506.