Apparatus

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sensors Mode-S transponder

8681B5

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA73NP · BOEING 737-800

Hex
8681B5
Octal
41500665
Decimal
8,815,029
Country
JP
Tail
JA73NP
Type
B738
Broadcasting now · callsign SKY148 · 3,350 ft
Flights observed
393
Distinct callsigns
20
Country
JP
Last broadcast
1h ago

Current position

8681B5 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 8681B5 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
SKY591 Skymark Airlines 10 2026-06-08
SKY597 Skymark Airlines 9 2026-06-10
SKY511 - 9 2026-06-20
SKY718 - 8 2026-06-21
SKY618 Skymark Airlines 8 2026-06-09
SKY177 - 8 2026-06-21
SKY523 - 7 2026-06-24
SKY521 - 7 2026-06-22
SKY729 Skymark Airlines 6 2026-06-09
SKY706 Skymark Airlines 6 2026-06-09
SKY613 Skymark Airlines 6 2026-06-10
SKY503 Skymark Airlines 6 2026-06-09
SKY185 - 6 2026-06-24
SKY184 - 6 2026-06-24
SKY171 - 6 2026-06-23
SKY170 - 6 2026-06-24
SKY112 - 6 2026-06-24
SKY795 - 5 2026-06-23
SKY794 - 5 2026-06-17
SKY765 - 5 2026-06-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SKY145 - Jul 14, 06:00 UTCJul 14, 06:55 UTC55m
2026-07-14 SKY105 HND → UKB Jul 14, 04:20 UTCJul 14, 05:10 UTC50m
2026-07-14 SKY710 - Jul 14, 01:55 UTCJul 14, 03:05 UTC1h 10m
2026-07-13 SKY705 - Jul 13, 23:30 UTCJul 14, 00:50 UTC1h 20m
2026-07-13 SKY8020 - Jul 13, 12:55 UTCJul 13, 15:55 UTC3h 0m
2026-06-25 SKY8020 - Jun 25, 10:30 UTCJun 25, 10:55 UTC25m
2026-06-25 SKY8020 - Jun 25, 07:54 UTCJun 25, 09:10 UTC1h 15m
2026-06-24 SKY523 - Jun 24, 10:35 UTCJun 25, 00:29 UTC13h 55m
2026-06-24 SKY112 - Jun 24, 07:34 UTCJun 24, 08:39 UTC1h 5m
2026-06-24 SKY185 - Jun 24, 05:40 UTCJun 24, 06:50 UTC1h 10m
2026-06-24 SKY184 - Jun 24, 03:55 UTCJun 24, 04:50 UTC55m
2026-06-24 SKY170 - Jun 24, 01:09 UTCJun 24, 03:10 UTC2h 0m
2026-06-23 SKY171 - Jun 23, 22:34 UTCJun 24, 00:15 UTC1h 40m
2026-06-23 SKY178 CTS → UKB Jun 23, 11:59 UTCJun 23, 13:45 UTC1h 45m
2026-06-23 SKY795 - Jun 23, 09:49 UTCJun 23, 11:04 UTC1h 15m
2026-06-23 SKY532 - Jun 23, 01:59 UTCJun 23, 08:45 UTC6h 45m
2026-06-23 SKY132 - Jun 23, 00:30 UTCJun 23, 01:04 UTC35m
2026-06-22 SKY301 - Jun 22, 21:54 UTCJun 22, 23:10 UTC1h 15m
2026-06-22 SKY521 HND → HND Jun 22, 08:44 UTCJun 22, 14:10 UTC5h 25m
2026-06-22 SKY716 - Jun 22, 06:15 UTCJun 22, 07:45 UTC1h 30m
2026-06-22 SKY713 - Jun 22, 03:50 UTCJun 22, 05:04 UTC1h 15m
2026-06-21 SKY512 - Jun 21, 21:24 UTCJun 22, 02:30 UTC5h 5m
2026-06-21 SKY768 CTS → NGO Jun 21, 11:55 UTCJun 21, 13:15 UTC1h 20m
2026-06-21 SKY727 - Jun 21, 09:44 UTCJun 21, 11:00 UTC1h 15m
2026-06-21 SKY718 - Jun 21, 06:29 UTCJun 21, 07:45 UTC1h 15m
2026-06-21 SKY177 - Jun 21, 03:44 UTCJun 21, 05:25 UTC1h 40m
2026-06-20 SKY511 - Jun 20, 22:00 UTCJun 21, 02:45 UTC4h 45m
2026-06-20 SKY730 CTS → HND Jun 20, 12:09 UTCJun 20, 13:24 UTC1h 15m
2026-06-20 SKY179 - Jun 20, 09:44 UTCJun 20, 11:20 UTC1h 35m
2026-06-20 SKY148 - Jun 20, 08:09 UTCJun 20, 08:59 UTC50m
2026-06-20 SKY145 - Jun 20, 06:10 UTCJun 20, 07:04 UTC55m
2026-06-20 SKY105 HND → UKB Jun 20, 04:20 UTCJun 20, 05:14 UTC55m
2026-06-20 SKY710 - Jun 20, 02:04 UTCJun 20, 03:19 UTC1h 15m
2026-06-19 SKY705 - Jun 19, 23:44 UTCJun 20, 01:05 UTC1h 20m
2026-06-19 SKY726 - Jun 19, 10:59 UTCJun 19, 12:09 UTC1h 10m
2026-06-19 SKY723 - Jun 19, 08:29 UTCJun 19, 09:44 UTC1h 15m
2026-06-19 SKY518 - Jun 19, 06:24 UTCJun 19, 07:14 UTC50m
2026-06-18 SKY501 - Jun 18, 23:30 UTCJun 18, 23:40 UTC10m
2026-06-18 SKY593 - Jun 18, 03:05 UTCJun 18, 03:35 UTC30m
2026-06-18 SKY153 - Jun 18, 01:00 UTCJun 18, 02:05 UTC1h 5m
2026-06-17 SKY152 - Jun 17, 22:55 UTCJun 17, 23:40 UTC45m
2026-06-17 SKY187 - Jun 17, 10:55 UTCJun 17, 12:00 UTC1h 5m
2026-06-17 SKY794 - Jun 17, 09:00 UTCJun 17, 10:00 UTC1h 0m
2026-06-17 SKY765 - Jun 17, 06:45 UTCJun 17, 08:10 UTC1h 25m
2026-06-17 SKY636 - Jun 17, 05:00 UTCJun 17, 05:40 UTC40m
2026-06-16 SKY131 - Jun 16, 23:50 UTCJun 17, 00:20 UTC30m
2026-06-16 SKY187 IBR → UKB Jun 16, 11:10 UTCJun 16, 12:10 UTC1h 0m
2026-06-16 SKY794 - Jun 16, 09:00 UTCJun 16, 10:00 UTC1h 0m
2026-06-16 SKY765 - Jun 16, 06:40 UTCJun 16, 08:00 UTC1h 20m
2026-06-16 SKY636 - Jun 16, 05:00 UTCJun 16, 05:40 UTC40m

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 JA73NP page for operator, model, and routing details .

Mode-S 8681B5 frequently asked

What is Mode-S code 8681B5?
8681B5 is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA73NP.
Where is Mode-S 8681B5 registered?
Mode-S code 8681B5 is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8681B5 broadcasting right now?
Yes. Mode-S 8681B5 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8681B5, octal 41500665, decimal 8,815,029.
What flights does 8681B5 operate?
Mode-S 8681B5 has broadcast 20 distinct callsigns, including SKY591, SKY597, SKY511, SKY718, SKY618.