Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

8681AB

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA73ND · BOEING 737-800

Hex
8681AB
Octal
41500653
Decimal
8,815,019
Country
JP
Tail
JA73ND
Type
B738
No current signal · last broadcast Jul 26, 11:45 UTC
Flights observed
444
Distinct callsigns
20
Country
JP
Last broadcast
Jul 26, 11:45 UTC

Last known position

Most recent position reported by Mode-S 8681AB.

Country allocation

The ICAO 24-bit address 8681AB 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
SKY720 - 6 2026-07-19
SKY712 - 6 2026-07-19
SKY309 Skymark Airlines 6 2026-07-24
SKY171 Skymark Airlines 6 2026-07-23
SKY762 Skymark Airlines 5 2026-07-25
SKY761 Skymark Airlines 5 2026-07-24
SKY717 - 5 2026-07-19
SKY591 - 5 2026-07-14
SKY185 Skymark Airlines 5 2026-07-24
SKY184 Skymark Airlines 5 2026-07-24
SKY178 - 5 2026-07-20
SKY175 - 5 2026-07-19
SKY170 Skymark Airlines 5 2026-07-24
SKY138 - 5 2026-07-25
SKY136 Skymark Airlines 5 2026-07-25
SKY112 Skymark Airlines 5 2026-07-24
SKY026 Skymark Airlines 5 2026-07-19
SKY014 - 5 2026-07-18
SKY012 Skymark Airlines 5 2026-05-20
SKY009 - 5 2026-05-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKY836 FUK → IBR Jul 26, 10:15 UTCJul 26, 11:45 UTC1h 30m
2026-07-26 SKY564 SHI → FUK Jul 26, 04:25 UTCJul 26, 09:00 UTC4h 36m
2026-07-26 SKY831 IBR → FUK Jul 26, 01:15 UTCJul 26, 02:50 UTC1h 35m
2026-07-25 SKY182 UKB → IBR Jul 25, 23:30 UTCJul 26, 00:25 UTC55m
2026-07-25 SKY138 - Jul 25, 06:40 UTCJul 25, 12:20 UTC5h 40m
2026-07-25 SKY136 KOJ → UKB Jul 25, 03:10 UTCJul 25, 05:55 UTC2h 45m
2026-07-25 SKY762 CTS → NGO Jul 25, 00:35 UTCJul 25, 01:50 UTC1h 15m
2026-07-24 SKY761 NGO → CTS Jul 24, 22:25 UTCJul 24, 23:45 UTC1h 20m
2026-07-24 SKY638 KOJ → NGO Jul 24, 12:50 UTCJul 24, 13:25 UTC35m
2026-07-24 SKY309 HND → KOJ Jul 24, 10:15 UTCJul 24, 11:20 UTC1h 5m
2026-07-24 SKY112 UKB → HND Jul 24, 07:35 UTCJul 24, 08:50 UTC1h 15m
2026-07-24 SKY185 IBR → UKB Jul 24, 05:30 UTCJul 24, 06:30 UTC1h 0m
2026-07-24 SKY184 UKB → IBR Jul 24, 03:40 UTCJul 24, 04:40 UTC1h 0m
2026-07-24 SKY170 CTS → UKB Jul 24, 01:10 UTCJul 24, 02:50 UTC1h 40m
2026-07-23 SKY171 UKB → CTS Jul 23, 22:40 UTCJul 24, 00:15 UTC1h 35m
2026-07-23 SKY598 OKA → UKB Jul 23, 11:40 UTCJul 23, 13:05 UTC1h 25m
2026-07-23 SKY595 - Jul 23, 10:20 UTCJul 23, 10:35 UTC15m
2026-07-23 SKY595 - Jul 23, 09:00 UTCJul 23, 09:35 UTC35m
2026-07-23 SKY172 - Jul 23, 06:25 UTCJul 23, 07:55 UTC1h 30m
2026-07-23 SKY793 IBR → CTS Jul 23, 04:15 UTCJul 23, 05:30 UTC1h 15m
2026-07-23 SKY792 CTS → IBR Jul 23, 02:15 UTCJul 23, 03:25 UTC1h 10m
2026-07-22 SKY173 UKB → CTS Jul 22, 23:45 UTCJul 23, 01:20 UTC1h 35m
2026-07-22 SKY187 - Jul 22, 11:10 UTCJul 22, 12:00 UTC50m
2026-07-21 SKY131 UKB → KOJ Jul 21, 23:50 UTCJul 22, 05:25 UTC5h 35m
2026-07-21 SKY590 OKA → UKB Jul 21, 21:25 UTCJul 21, 22:55 UTC1h 30m
2026-07-21 SKY523 HND → OKA Jul 21, 11:30 UTCJul 21, 11:50 UTC20m
2026-07-21 SKY523 HND → OKA Jul 21, 09:45 UTCJul 21, 10:25 UTC40m
2026-07-21 SKY112 UKB → HND Jul 21, 07:35 UTCJul 21, 08:40 UTC1h 5m
2026-07-21 SKY185 IBR → UKB Jul 21, 05:20 UTCJul 21, 06:25 UTC1h 5m
2026-07-21 SKY184 UKB → IBR Jul 21, 03:30 UTCJul 21, 04:20 UTC50m
2026-07-21 SKY170 CTS → UKB Jul 21, 01:00 UTCJul 21, 02:35 UTC1h 35m
2026-07-20 SKY171 - Jul 20, 22:35 UTCJul 21, 00:05 UTC1h 29m
2026-07-20 SKY178 - Jul 20, 11:50 UTCJul 20, 13:25 UTC1h 35m
2026-07-20 SKY795 IBR → CTS Jul 20, 09:45 UTCJul 20, 10:50 UTC1h 5m
2026-07-20 SKY532 OKA → IBR Jul 20, 06:50 UTCJul 20, 08:55 UTC2h 5m
2026-07-20 SKY546 - Jul 20, 05:30 UTCJul 20, 05:40 UTC10m
2026-07-20 SKY163 - Jul 20, 02:00 UTCJul 20, 03:35 UTC1h 35m
2026-07-20 SKY132 KOJ → UKB Jul 20, 00:20 UTCJul 20, 01:05 UTC45m
2026-07-19 SKY301 HND → KOJ Jul 19, 21:55 UTCJul 19, 23:05 UTC1h 10m
2026-07-19 SKY026 FUK → HND Jul 19, 12:35 UTCJul 19, 13:55 UTC1h 20m
2026-07-19 SKY025 - Jul 19, 10:15 UTCJul 19, 11:20 UTC1h 5m
2026-07-19 SKY720 - Jul 19, 07:35 UTCJul 19, 08:55 UTC1h 20m
2026-07-19 SKY717 - Jul 19, 05:20 UTCJul 19, 06:35 UTC1h 15m
2026-07-19 SKY712 - Jul 19, 03:00 UTCJul 19, 04:20 UTC1h 20m
2026-07-19 SKY175 - Jul 19, 00:30 UTCJul 19, 02:05 UTC1h 35m
2026-07-18 SKY140 - Jul 18, 22:45 UTCJul 18, 23:35 UTC50m
2026-07-18 SKY147 - Jul 18, 10:55 UTCJul 18, 11:45 UTC50m
2026-07-18 SKY113 HND → UKB Jul 18, 09:10 UTCJul 18, 10:10 UTC1h 0m
2026-07-18 SKY014 - Jul 18, 06:05 UTCJul 18, 07:35 UTC1h 30m
2026-07-18 SKY011 HND → FUK Jul 18, 03:10 UTCJul 18, 04:15 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 JA73ND page for operator, model, and routing details .

Mode-S 8681AB frequently asked

What is Mode-S code 8681AB?
8681AB is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA73ND.
Where is Mode-S 8681AB registered?
Mode-S code 8681AB is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8681AB broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 11:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8681AB, octal 41500653, decimal 8,815,019.
What flights does 8681AB operate?
Mode-S 8681AB has broadcast 20 distinct callsigns, including SKY720, SKY712, SKY309, SKY171, SKY762.