Apparatus

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sensors Mode-S transponder

45AB21

ICAO 24-bit transponder address · allocated to Denmark

Currently assigned to OY-JYA · BOEING 737-800

Hex
45AB21
Octal
21325441
Decimal
4,565,793
Country
DK
Tail
OY-JYA
Type
B738
No current signal · last broadcast 5h ago
Flights observed
360
Distinct callsigns
20
Country
DK
Last broadcast
5h ago

Last known position

Most recent position reported by Mode-S 45AB21.

Country allocation

The ICAO 24-bit address 45AB21 falls within the block assigned to Denmark (DK) by ICAO Annex 10, Volume III. Every aircraft registered in Denmark 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
FIN33V - 17 2026-07-13
FIN8AM - 16 2026-07-13
FIN8U Finnair 11 2026-07-02
FIN1HA - 11 2026-07-02
FIN9AP - 10 2026-07-09
FIN4KG - 10 2026-07-09
FIN65M - 6 2026-07-10
FIN5H - 6 2026-07-10
FIN4EA Finnair 6 2026-05-08
FIN9ML Finnair 5 2026-04-29
FIN30T Finnair 5 2026-05-08
JTD532 Jet Time 4 2026-06-19
JTD531 Jet Time 4 2026-06-19
FIN9TA - 4 2026-07-05
FIN8RK - 4 2026-07-02
FIN8KR - 4 2026-07-05
FIN7RX - 4 2026-07-02
FIN60H - 4 2026-07-02
FIN1PM - 4 2026-07-02
FIN1AB Finnair 4 2026-04-29

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 FIN1LP FRA → HEL Jul 13, 18:10 UTCJul 13, 20:10 UTC2h 0m
2026-07-13 FIN2K HEL → FRA Jul 13, 14:25 UTCJul 13, 16:40 UTC2h 15m
2026-07-13 FIN33V - Jul 13, 09:25 UTCJul 13, 12:30 UTC3h 5m
2026-07-13 FIN8AM HEL → KEF Jul 13, 04:35 UTCJul 13, 07:50 UTC3h 15m
2026-07-12 FIN7X - Jul 12, 18:10 UTCJul 12, 21:05 UTC2h 55m
2026-07-12 FIN8KT HEL → NCE Jul 12, 13:50 UTCJul 12, 16:50 UTC3h 0m
2026-07-12 FIN33V - Jul 12, 09:20 UTCJul 12, 12:25 UTC3h 5m
2026-07-12 FIN8AM HEL → KEF Jul 12, 04:35 UTCJul 12, 07:55 UTC3h 20m
2026-07-11 FIN7LK - Jul 11, 18:20 UTCJul 11, 21:10 UTC2h 50m
2026-07-11 FIN60A HEL → BLQ Jul 11, 14:40 UTCJul 11, 17:10 UTC2h 30m
2026-07-11 FIN33V KEF → HEL Jul 11, 09:45 UTCJul 11, 12:45 UTC3h 0m
2026-07-11 FIN8AM HEL → KEF Jul 11, 04:55 UTCJul 11, 08:15 UTC3h 20m
2026-07-10 FIN65M VIE → HEL Jul 10, 17:20 UTCJul 10, 19:20 UTC2h 0m
2026-07-10 FIN5H HEL → VIE Jul 10, 14:10 UTCJul 10, 16:05 UTC1h 55m
2026-07-10 FIN33V KEF → HEL Jul 10, 09:35 UTCJul 10, 12:40 UTC3h 5m
2026-07-10 FIN8AM HEL → KEF Jul 10, 04:45 UTCJul 10, 08:00 UTC3h 15m
2026-07-09 FIN4KG - Jul 9, 17:30 UTCJul 9, 20:05 UTC2h 35m
2026-07-09 FIN9AP HEL → VCE Jul 9, 13:55 UTCJul 9, 16:15 UTC2h 20m
2026-07-09 FIN8LF ARN → HEL Jul 9, 11:45 UTCJul 9, 12:35 UTC50m
2026-07-09 FIN8AZ HEL → ARN Jul 9, 10:10 UTCJul 9, 10:50 UTC40m
2026-07-09 FIN9DZ KRK → HEL Jul 9, 07:05 UTCJul 9, 08:45 UTC1h 40m
2026-07-09 FIN5AH HEL → KRK Jul 9, 04:35 UTCJul 9, 06:10 UTC1h 35m
2026-07-08 FIN5NX OSL → HEL Jul 8, 16:15 UTCJul 8, 17:20 UTC1h 5m
2026-07-08 FIN7BV HEL → OSL Jul 8, 13:50 UTCJul 8, 15:05 UTC1h 15m
2026-07-08 FIN67E VIE → HEL Jul 8, 09:50 UTCJul 8, 11:55 UTC2h 5m
2026-07-08 FIN6RL HEL → VIE Jul 8, 06:30 UTCJul 8, 08:30 UTC2h 0m
2026-07-07 FIN4KG - Jul 7, 17:40 UTCJul 7, 20:20 UTC2h 40m
2026-07-07 FIN9AP HEL → VCE Jul 7, 13:50 UTCJul 7, 16:20 UTC2h 30m
2026-07-07 FIN33V - Jul 7, 09:05 UTCJul 7, 12:10 UTC3h 5m
2026-07-07 FIN8AM HEL → KEF Jul 7, 04:45 UTCJul 7, 08:00 UTC3h 15m
2026-07-06 FIN6D - Jul 6, 17:00 UTCJul 6, 18:45 UTC1h 45m
2026-07-06 FIN1163 HEL → KRK Jul 6, 14:30 UTCJul 6, 16:05 UTC1h 35m
2026-07-06 FIN34M - Jul 6, 09:15 UTCJul 6, 12:25 UTC3h 10m
2026-07-06 FIN1791 - Jul 6, 04:35 UTCJul 6, 06:00 UTC1h 25m
2026-07-05 FIN6PR - Jul 5, 17:40 UTCJul 5, 18:55 UTC1h 15m
2026-07-05 FIN1BL HEL → CPH Jul 5, 15:30 UTCJul 5, 16:50 UTC1h 20m
2026-07-05 FIN822 ARN → HEL Jul 5, 13:35 UTCJul 5, 14:15 UTC40m
2026-07-05 FIN9DK HEL → ARN Jul 5, 11:40 UTCJul 5, 12:30 UTC50m
2026-07-05 FIN8KR - Jul 5, 08:05 UTCJul 5, 10:35 UTC2h 30m
2026-07-05 FIN9TA - Jul 5, 04:15 UTCJul 5, 06:45 UTC2h 30m
2026-07-04 FIN4KG - Jul 4, 18:20 UTCJul 4, 20:55 UTC2h 35m
2026-07-04 FIN9AP - Jul 4, 13:55 UTCJul 4, 16:25 UTC2h 30m
2026-07-04 FIN33V KEF → HEL Jul 4, 09:15 UTCJul 4, 12:15 UTC3h 0m
2026-07-04 FIN8AM HEL → KEF Jul 4, 04:35 UTCJul 4, 07:45 UTC3h 10m
2026-07-03 FIN5NX - Jul 3, 15:45 UTCJul 3, 16:50 UTC1h 5m
2026-07-03 FIN7BV HEL → OSL Jul 3, 13:35 UTCJul 3, 14:40 UTC1h 5m
2026-07-03 FIN67E VIE → HEL Jul 3, 09:50 UTCJul 3, 11:40 UTC1h 50m
2026-07-03 FIN6RL HEL → VIE Jul 3, 06:40 UTCJul 3, 08:50 UTC2h 10m
2026-07-02 FIN8U BUD → HEL Jul 2, 17:15 UTCJul 2, 19:15 UTC2h 0m
2026-07-02 FIN1HA HEL → BUD Jul 2, 14:15 UTCJul 2, 16:25 UTC2h 10m

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 OY-JYA page for operator, model, and routing details .

Mode-S 45AB21 frequently asked

What is Mode-S code 45AB21?
45AB21 is an ICAO 24-bit transponder address. Allocated to Denmark. Assigned to OY-JYA.
Where is Mode-S 45AB21 registered?
Mode-S code 45AB21 is allocated to Denmark (DK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 45AB21 broadcasting right now?
No active broadcast right now. Last signal was 5h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 45AB21, octal 21325441, decimal 4,565,793.
What flights does 45AB21 operate?
Mode-S 45AB21 has broadcast 20 distinct callsigns, including FIN33V, FIN8AM, FIN8U, FIN1HA, FIN9AP.