Apparatus

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sensors Mode-S transponder

45CF23

ICAO 24-bit transponder address · allocated to Denmark

Currently assigned to OY-SYC · BOEING 767-300

Hex
45CF23
Octal
21347443
Decimal
4,575,011
Country
DK
Tail
OY-SYC
Type
B763
No current signal · last broadcast Jul 24, 23:00 UTC
Flights observed
274
Distinct callsigns
10
Country
DK
Last broadcast
Jul 24, 23:00 UTC

Last known position

Most recent position reported by Mode-S 45CF23.

Country allocation

The ICAO 24-bit address 45CF23 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 10 distinct

Callsign Airline Flights Last seen
UPS292 United Parcel Service 115 2026-07-24
UPS291 United Parcel Service 112 2026-07-24
SRR6402 - 18 2026-06-15
SRR6401 - 17 2026-06-15
SRR6498 Star Air 4 2026-05-28
UPS275 - 2 2026-06-25
UPS274 - 2 2026-06-25
SRR6497 Star Air 2 2026-05-28
UPS293 - 1 2026-05-14
SRR7801 - 1 2026-06-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-24 UPS291 ARN → HEL Jul 24, 22:05 UTCJul 24, 23:00 UTC55m
2026-07-24 UPS291 ARN → HEL Jul 24, 19:10 UTCJul 24, 20:25 UTC1h 15m
2026-07-24 UPS292 CGN → HEL Jul 24, 03:45 UTCJul 24, 05:00 UTC1h 15m
2026-07-24 UPS292 CGN → HEL Jul 24, 01:45 UTCJul 24, 02:45 UTC1h 0m
2026-07-23 UPS291 ARN → HEL Jul 23, 21:40 UTCJul 23, 22:35 UTC55m
2026-07-23 UPS291 ARN → HEL Jul 23, 19:10 UTCJul 23, 20:20 UTC1h 10m
2026-07-23 UPS292 CGN → HEL Jul 23, 03:50 UTCJul 23, 05:10 UTC1h 20m
2026-07-23 UPS292 CGN → HEL Jul 23, 01:45 UTCJul 23, 02:50 UTC1h 5m
2026-07-22 UPS291 ARN → HEL Jul 22, 21:35 UTCJul 22, 22:35 UTC1h 0m
2026-07-22 UPS291 ARN → HEL Jul 22, 19:15 UTCJul 22, 20:30 UTC1h 15m
2026-07-22 UPS292 CGN → HEL Jul 22, 03:40 UTCJul 22, 04:55 UTC1h 15m
2026-07-22 UPS292 CGN → HEL Jul 22, 01:50 UTCJul 22, 02:45 UTC55m
2026-07-21 UPS291 ARN → HEL Jul 21, 21:35 UTCJul 21, 22:40 UTC1h 5m
2026-07-21 UPS291 ARN → HEL Jul 21, 19:15 UTCJul 21, 20:25 UTC1h 10m
2026-07-21 UPS292 CGN → HEL Jul 21, 03:40 UTCJul 21, 05:05 UTC1h 25m
2026-07-21 UPS292 CGN → HEL Jul 21, 01:40 UTCJul 21, 02:45 UTC1h 5m
2026-07-20 UPS291 ARN → HEL Jul 20, 20:50 UTCJul 20, 22:30 UTC1h 40m
2026-07-20 UPS291 ARN → HEL Jul 20, 19:00 UTCJul 20, 19:45 UTC45m
2026-07-20 UPS292 CGN → HEL Jul 20, 03:15 UTCJul 20, 03:50 UTC35m
2026-07-20 UPS292 CGN → HEL Jul 20, 00:20 UTCJul 20, 01:50 UTC1h 30m
2026-07-17 UPS291 - Jul 17, 21:30 UTCJul 17, 22:55 UTC1h 25m
2026-07-17 UPS291 - Jul 17, 19:09 UTCJul 17, 20:29 UTC1h 20m
2026-07-17 UPS292 CGN → HEL Jul 17, 03:34 UTCJul 17, 04:44 UTC1h 10m
2026-07-17 UPS292 CGN → HEL Jul 17, 01:45 UTCJul 17, 02:39 UTC55m
2026-07-16 UPS291 - Jul 16, 21:35 UTCJul 16, 22:35 UTC1h 0m
2026-07-16 UPS291 - Jul 16, 19:10 UTCJul 16, 20:25 UTC1h 15m
2026-07-16 UPS292 - Jul 16, 03:35 UTCJul 16, 04:55 UTC1h 20m
2026-07-16 UPS292 - Jul 16, 01:50 UTCJul 16, 02:50 UTC1h 0m
2026-07-15 UPS291 - Jul 15, 21:35 UTCJul 15, 22:40 UTC1h 5m
2026-07-15 UPS291 - Jul 15, 19:10 UTCJul 15, 20:20 UTC1h 10m
2026-07-15 UPS292 - Jul 15, 03:35 UTCJul 15, 04:50 UTC1h 15m
2026-07-15 UPS292 - Jul 15, 01:55 UTCJul 15, 02:55 UTC1h 0m
2026-07-14 UPS291 - Jul 14, 21:35 UTCJul 14, 22:35 UTC1h 0m
2026-07-14 UPS291 - Jul 14, 19:10 UTCJul 14, 20:20 UTC1h 10m
2026-07-14 UPS292 - Jul 14, 03:40 UTCJul 14, 05:05 UTC1h 25m
2026-07-14 UPS292 - Jul 14, 01:50 UTCJul 14, 02:50 UTC1h 0m
2026-07-13 UPS291 - Jul 13, 20:50 UTCJul 13, 22:35 UTC1h 45m
2026-07-13 UPS291 - Jul 13, 19:00 UTCJul 13, 19:40 UTC40m
2026-07-13 UPS292 - Jul 13, 02:50 UTCJul 13, 03:25 UTC35m
2026-07-13 UPS292 - Jul 13, 00:05 UTCJul 13, 01:45 UTC1h 40m
2026-07-10 UPS291 - Jul 10, 21:30 UTCJul 10, 22:30 UTC1h 0m
2026-07-10 UPS291 - Jul 10, 19:10 UTCJul 10, 20:20 UTC1h 10m
2026-07-10 UPS292 - Jul 10, 03:50 UTCJul 10, 05:10 UTC1h 20m
2026-07-10 UPS292 - Jul 10, 01:50 UTCJul 10, 02:55 UTC1h 5m
2026-07-09 UPS291 - Jul 9, 21:25 UTCJul 9, 22:30 UTC1h 5m
2026-07-09 UPS291 - Jul 9, 19:05 UTCJul 9, 20:15 UTC1h 10m
2026-07-09 UPS292 - Jul 9, 03:40 UTCJul 9, 04:55 UTC1h 15m
2026-07-09 UPS292 - Jul 9, 01:45 UTCJul 9, 02:45 UTC1h 0m
2026-07-08 UPS291 - Jul 8, 21:40 UTCJul 8, 22:55 UTC1h 15m
2026-07-08 UPS291 - Jul 8, 19:10 UTCJul 8, 20:20 UTC1h 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-SYC page for operator, model, and routing details .

Mode-S 45CF23 frequently asked

What is Mode-S code 45CF23?
45CF23 is an ICAO 24-bit transponder address. Allocated to Denmark. Assigned to OY-SYC.
Where is Mode-S 45CF23 registered?
Mode-S code 45CF23 is allocated to Denmark (DK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 45CF23 broadcasting right now?
No active broadcast right now. Last signal was Jul 24, 23:00 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 45CF23, octal 21347443, decimal 4,575,011.
What flights does 45CF23 operate?
Mode-S 45CF23 has broadcast 10 distinct callsigns, including UPS292, UPS291, SRR6402, SRR6401, SRR6498.