Apparatus

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sensors Mode-S transponder

8681BD

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA73NX · BOEING 737-800

Hex
8681BD
Octal
41500675
Decimal
8,815,037
Country
JP
Tail
JA73NX
Type
B738
No current signal · last broadcast 5d ago
Flights observed
443
Distinct callsigns
20
Country
JP
Last broadcast
5d ago

Last known position

Most recent position reported by Mode-S 8681BD.

Country allocation

The ICAO 24-bit address 8681BD 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
SKY599 Skymark Airlines 8 2026-07-04
SKY519 - 8 2026-07-04
SKY794 Skymark Airlines 7 2026-07-26
SKY187 Skymark Airlines 7 2026-07-26
SKY142 - 7 2026-06-26
SKY141 - 7 2026-06-26
SKY765 Skymark Airlines 6 2026-07-26
SKY523 Skymark Airlines 6 2026-07-25
SKY183 - 6 2026-06-25
SKY157 - 6 2026-07-17
SKY156 - 6 2026-07-17
SKY131 Skymark Airlines 6 2026-07-25
SKY108 - 6 2026-06-26
SKY836 - 5 2026-07-18
SKY831 - 5 2026-07-18
SKY793 Skymark Airlines 5 2026-07-24
SKY792 Skymark Airlines 5 2026-07-24
SKY714 - 5 2026-07-17
SKY711 - 5 2026-07-17
SKY595 - 5 2026-07-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKY187 IBR → UKB Jul 26, 11:10 UTCJul 26, 12:10 UTC1h 0m
2026-07-26 SKY794 CTS → IBR Jul 26, 09:20 UTCJul 26, 10:20 UTC1h 0m
2026-07-26 SKY765 NGO → CTS Jul 26, 07:05 UTCJul 26, 08:20 UTC1h 15m
2026-07-26 SKY636 KOJ → NGO Jul 26, 05:00 UTCJul 26, 05:35 UTC35m
2026-07-25 SKY131 UKB → KOJ Jul 25, 23:50 UTCJul 26, 00:20 UTC30m
2026-07-25 SKY590 OKA → UKB Jul 25, 22:15 UTCJul 25, 22:55 UTC40m
2026-07-25 SKY590 OKA → UKB Jul 25, 21:20 UTCJul 25, 21:30 UTC10m
2026-07-25 SKY523 HND → OKA Jul 25, 10:20 UTCJul 25, 12:25 UTC2h 5m
2026-07-25 SKY112 UKB → HND Jul 25, 08:20 UTCJul 25, 09:10 UTC50m
2026-07-25 SKY185 IBR → UKB Jul 25, 05:25 UTCJul 25, 06:30 UTC1h 5m
2026-07-25 SKY184 UKB → IBR Jul 25, 03:35 UTCJul 25, 04:25 UTC50m
2026-07-25 SKY170 CTS → UKB Jul 25, 01:10 UTCJul 25, 02:45 UTC1h 35m
2026-07-24 SKY171 UKB → CTS Jul 24, 22:40 UTCJul 25, 00:15 UTC1h 35m
2026-07-24 SKY598 OKA → UKB Jul 24, 11:35 UTCJul 24, 13:10 UTC1h 35m
2026-07-24 SKY595 - Jul 24, 10:10 UTCJul 24, 10:30 UTC20m
2026-07-24 SKY595 - Jul 24, 08:50 UTCJul 24, 09:20 UTC30m
2026-07-24 SKY172 CTS → UKB Jul 24, 06:25 UTCJul 24, 08:00 UTC1h 35m
2026-07-24 SKY793 IBR → CTS Jul 24, 04:15 UTCJul 24, 05:30 UTC1h 15m
2026-07-24 SKY792 CTS → IBR Jul 24, 02:25 UTCJul 24, 03:25 UTC1h 0m
2026-07-23 SKY173 UKB → CTS Jul 23, 23:50 UTCJul 24, 01:40 UTC1h 50m
2026-07-23 SKY138 - Jul 23, 11:45 UTCJul 23, 12:20 UTC35m
2026-07-23 SKY135 UKB → KOJ Jul 23, 06:35 UTCJul 23, 07:10 UTC35m
2026-07-23 SKY136 KOJ → UKB Jul 23, 05:15 UTCJul 23, 05:50 UTC35m
2026-07-23 SKY637 NGO → KOJ Jul 23, 03:10 UTCJul 23, 03:45 UTC35m
2026-07-23 SKY762 CTS → NGO Jul 23, 00:30 UTCJul 23, 01:50 UTC1h 20m
2026-07-22 SKY761 - Jul 22, 22:20 UTCJul 22, 23:40 UTC1h 20m
2026-07-22 SKY558 OKA → NGO Jul 22, 12:15 UTCJul 22, 13:50 UTC1h 35m
2026-07-22 SKY613 HND → SHI Jul 22, 02:25 UTCJul 22, 10:25 UTC8h 0m
2026-07-21 SKY706 CTS → HND Jul 21, 23:25 UTCJul 22, 00:45 UTC1h 20m
2026-07-21 SKY729 HND → CTS Jul 21, 12:10 UTCJul 21, 13:20 UTC1h 10m
2026-07-21 SKY520 OKA → HND Jul 21, 08:10 UTCJul 21, 10:20 UTC2h 10m
2026-07-21 SKY557 - Jul 21, 05:15 UTCJul 21, 06:55 UTC1h 40m
2026-07-21 SKY552 - Jul 21, 03:45 UTCJul 21, 04:05 UTC20m
2026-07-21 SKY552 - Jul 21, 02:25 UTCJul 21, 02:35 UTC10m
2026-07-20 SKY513 HND → OKA Jul 20, 23:00 UTCJul 21, 01:10 UTC2h 10m
2026-07-20 SKY308 KOJ → HND Jul 20, 11:35 UTCJul 20, 12:50 UTC1h 15m
2026-07-20 SKY307 - Jul 20, 06:50 UTCJul 20, 07:55 UTC1h 5m
2026-07-19 SKY300 UKB → HND Jul 19, 11:45 UTCJul 19, 23:50 UTC12h 5m
2026-07-19 SKY176 - Jul 19, 09:15 UTCJul 19, 11:00 UTC1h 45m
2026-07-19 SKY775 FUK → CTS Jul 19, 06:00 UTCJul 19, 08:00 UTC2h 0m
2026-07-19 SKY772 - Jul 19, 02:00 UTCJul 19, 03:40 UTC1h 40m
2026-07-19 SKY791 IBR → CTS Jul 19, 00:00 UTCJul 19, 01:05 UTC1h 5m
2026-07-18 SKY836 - Jul 18, 10:00 UTCJul 18, 11:20 UTC1h 20m
2026-07-18 SKY564 - Jul 18, 04:50 UTCJul 18, 08:35 UTC3h 45m
2026-07-18 SKY563 - Jul 18, 04:05 UTCJul 18, 04:15 UTC10m
2026-07-18 SKY831 - Jul 18, 01:15 UTCJul 18, 02:25 UTC1h 10m
2026-07-17 SKY182 - Jul 17, 23:25 UTCJul 18, 00:19 UTC55m
2026-07-17 SKY157 - Jul 17, 10:50 UTCJul 17, 11:55 UTC1h 5m
2026-07-17 SKY156 - Jul 17, 08:49 UTCJul 17, 09:45 UTC55m
2026-07-17 SKY109 HND → UKB Jul 17, 07:05 UTCJul 17, 07:55 UTC50m

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 JA73NX page for operator, model, and routing details .

Mode-S 8681BD frequently asked

What is Mode-S code 8681BD?
8681BD is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA73NX.
Where is Mode-S 8681BD registered?
Mode-S code 8681BD is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8681BD broadcasting right now?
No active broadcast right now. Last signal was 5d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8681BD, octal 41500675, decimal 8,815,037.
What flights does 8681BD operate?
Mode-S 8681BD has broadcast 20 distinct callsigns, including SKY599, SKY519, SKY794, SKY187, SKY142.