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 Jul 26, 20:45 UTC
Flights observed
416
Distinct callsigns
20
Country
DK
Last broadcast
Jul 26, 20:45 UTC

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
FIN8AM - 27 2026-07-26
FIN33V Finnair 26 2026-07-26
FIN9AP Finnair 14 2026-07-25
FIN8U Finnair 14 2026-07-24
FIN4KG - 14 2026-07-25
FIN1HA Finnair 14 2026-07-24
FIN65M - 7 2026-07-17
FIN5H - 7 2026-07-17
FIN8RK Finnair 6 2026-07-22
FIN4EA Finnair 6 2026-05-08
FIN9ML Finnair 5 2026-04-29
FIN7RX - 5 2026-07-15
FIN60H - 5 2026-07-15
FIN30T Finnair 5 2026-05-08
FIN1PM - 5 2026-07-15
JTD532 Jet Time 4 2026-06-19
JTD531 Jet Time 4 2026-06-19
FIN9TA - 4 2026-07-05
FIN8KT Finnair 4 2026-07-26
FIN8KR - 4 2026-07-05

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 FIN7X NCE → HEL Jul 26, 17:50 UTCJul 26, 20:45 UTC2h 55m
2026-07-26 FIN8KT HEL → NCE Jul 26, 13:30 UTCJul 26, 16:40 UTC3h 10m
2026-07-26 FIN33V KEF → HEL Jul 26, 09:00 UTCJul 26, 12:05 UTC3h 5m
2026-07-26 FIN8AM - Jul 26, 07:15 UTCJul 26, 07:50 UTC35m
2026-07-26 FIN8AM - Jul 26, 04:35 UTCJul 26, 06:00 UTC1h 25m
2026-07-25 FIN4KG - Jul 25, 17:50 UTCJul 25, 20:20 UTC2h 30m
2026-07-25 FIN9AP HEL → VCE Jul 25, 13:50 UTCJul 25, 16:25 UTC2h 35m
2026-07-25 FIN33V KEF → HEL Jul 25, 09:25 UTCJul 25, 12:30 UTC3h 5m
2026-07-25 FIN8AM HEL → KEF Jul 25, 04:30 UTCJul 25, 07:50 UTC3h 20m
2026-07-24 FIN8U BUD → HEL Jul 24, 16:40 UTCJul 24, 18:50 UTC2h 10m
2026-07-24 FIN1HA HEL → BUD Jul 24, 13:50 UTCJul 24, 15:40 UTC1h 50m
2026-07-24 FIN33V KEF → HEL Jul 24, 09:15 UTCJul 24, 12:10 UTC2h 55m
2026-07-24 FIN8AM HEL → KEF Jul 24, 04:35 UTCJul 24, 08:00 UTC3h 25m
2026-07-23 FIN7X NCE → HEL Jul 23, 17:55 UTCJul 23, 21:05 UTC3h 10m
2026-07-23 FIN8KT HEL → NCE Jul 23, 13:25 UTCJul 23, 16:10 UTC2h 45m
2026-07-23 FIN33V KEF → HEL Jul 23, 09:20 UTCJul 23, 12:15 UTC2h 55m
2026-07-23 FIN8AM HEL → KEF Jul 23, 04:35 UTCJul 23, 08:00 UTC3h 25m
2026-07-22 FIN8U BUD → HEL Jul 22, 16:55 UTCJul 22, 19:00 UTC2h 5m
2026-07-22 FIN1HA HEL → BUD Jul 22, 14:00 UTCJul 22, 16:00 UTC2h 0m
2026-07-22 FIN76U OSL → HEL Jul 22, 11:15 UTCJul 22, 12:25 UTC1h 10m
2026-07-22 FIN8RK HEL → CPH Jul 22, 03:40 UTCJul 22, 04:55 UTC1h 15m
2026-07-21 FIN4KG - Jul 21, 18:00 UTCJul 21, 20:40 UTC2h 40m
2026-07-21 FIN9AP HEL → VCE Jul 21, 14:05 UTCJul 21, 16:40 UTC2h 35m
2026-07-21 FIN33V KEF → HEL Jul 21, 09:40 UTCJul 21, 12:35 UTC2h 55m
2026-07-21 FIN8AM HEL → KEF Jul 21, 04:45 UTCJul 21, 08:15 UTC3h 30m
2026-07-20 FIN7LK BLQ → HEL Jul 20, 18:00 UTCJul 20, 20:35 UTC2h 35m
2026-07-20 FIN60A HEL → BLQ Jul 20, 14:05 UTCJul 20, 16:45 UTC2h 40m
2026-07-20 FIN33V KEF → HEL Jul 20, 09:45 UTCJul 20, 12:40 UTC2h 55m
2026-07-20 FIN8AM HEL → KEF Jul 20, 04:50 UTCJul 20, 08:15 UTC3h 25m
2026-07-19 FIN8U BUD → HEL Jul 19, 16:40 UTCJul 19, 18:30 UTC1h 50m
2026-07-19 FIN1HA HEL → BUD Jul 19, 13:35 UTCJul 19, 15:45 UTC2h 10m
2026-07-19 FIN33V KEF → HEL Jul 19, 09:20 UTCJul 19, 12:15 UTC2h 55m
2026-07-19 FIN8AM - Jul 19, 07:20 UTCJul 19, 07:50 UTC30m
2026-07-19 FIN8AM - Jul 19, 04:30 UTCJul 19, 06:10 UTC1h 40m
2026-07-18 FIN4KG - Jul 18, 18:25 UTCJul 18, 20:50 UTC2h 25m
2026-07-18 FIN9AP - Jul 18, 14:00 UTCJul 18, 16:50 UTC2h 50m
2026-07-18 FIN67E VIE → HEL Jul 18, 10:20 UTCJul 18, 12:20 UTC2h 0m
2026-07-18 FIN6RL HEL → VIE Jul 18, 06:30 UTCJul 18, 08:45 UTC2h 15m
2026-07-17 FIN65M - Jul 17, 18:44 UTCJul 17, 20:50 UTC2h 5m
2026-07-17 FIN5H HEL → VIE Jul 17, 14:15 UTCJul 17, 16:29 UTC2h 15m
2026-07-17 FIN33V - Jul 17, 09:20 UTCJul 17, 12:25 UTC3h 5m
2026-07-17 FIN8AM HEL → KEF Jul 17, 04:35 UTCJul 17, 08:00 UTC3h 25m
2026-07-16 FIN4KG - Jul 16, 18:40 UTCJul 16, 21:10 UTC2h 30m
2026-07-16 FIN9AP - Jul 16, 14:20 UTCJul 16, 17:00 UTC2h 40m
2026-07-16 FIN33V KEF → HEL Jul 16, 09:40 UTCJul 16, 12:34 UTC2h 55m
2026-07-16 FIN8AM HEL → KEF Jul 16, 04:35 UTCJul 16, 08:00 UTC3h 25m
2026-07-15 FIN26V - Jul 15, 17:50 UTCJul 15, 20:35 UTC2h 45m
2026-07-15 FIN9YC HEL → DUB Jul 15, 14:00 UTCJul 15, 16:40 UTC2h 40m
2026-07-15 FIN60H - Jul 15, 11:00 UTCJul 15, 12:20 UTC1h 20m
2026-07-15 FIN1PM HEL → CPH Jul 15, 08:40 UTCJul 15, 09:55 UTC1h 15m

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 Jul 26, 20:45 UTC.
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 FIN8AM, FIN33V, FIN9AP, FIN8U, FIN4KG.