Apparatus

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sensors Mode-S transponder

45B423

ICAO 24-bit transponder address · allocated to Denmark

Currently assigned to OY-MAC · BOEING 777-200LR

Hex
45B423
Octal
21332043
Decimal
4,568,099
Country
DK
Tail
OY-MAC
Type
B77L
No current signal · last broadcast 17h ago
Flights observed
166
Distinct callsigns
2
Country
DK
Last broadcast
17h ago

Last known position

Most recent position reported by Mode-S 45B423.

Country allocation

The ICAO 24-bit address 45B423 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 2 distinct

Callsign Airline Flights Last seen
SRR902 - 114 2026-07-13
SRR901 - 52 2026-07-12

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 SRR902 CVT → BLL Jul 13, 17:10 UTCJul 13, 18:20 UTC1h 10m
2026-07-13 SRR902 - Jul 13, 10:15 UTCJul 13, 15:20 UTC5h 5m
2026-07-12 SRR901 - Jul 12, 06:15 UTCJul 12, 10:01 UTC3h 45m
2026-07-11 SRR902 - Jul 11, 15:05 UTCJul 11, 16:15 UTC1h 10m
2026-07-11 SRR902 - Jul 11, 07:25 UTCJul 11, 12:40 UTC5h 15m
2026-07-10 SRR902 - Jul 10, 09:20 UTCJul 11, 08:40 UTC23h 20m
2026-07-10 SRR901 - Jul 10, 06:20 UTCJul 10, 10:00 UTC3h 40m
2026-07-09 SRR902 BHX → BLL Jul 9, 15:10 UTCJul 9, 16:25 UTC1h 15m
2026-07-09 SRR902 - Jul 9, 07:30 UTCJul 9, 12:40 UTC5h 10m
2026-07-08 SRR902 - Jul 8, 09:45 UTCJul 9, 08:45 UTC23h 0m
2026-07-08 SRR901 - Jul 8, 06:30 UTCJul 8, 10:15 UTC3h 45m
2026-07-07 SRR902 BHX → BLL Jul 7, 15:00 UTCJul 7, 16:15 UTC1h 15m
2026-07-07 SRR902 - Jul 7, 07:30 UTCJul 7, 12:45 UTC5h 15m
2026-07-06 SRR902 - Jul 6, 09:10 UTCJul 7, 08:45 UTC23h 35m
2026-07-06 SRR901 - Jul 6, 06:15 UTCJul 6, 10:00 UTC3h 45m
2026-07-05 SRR902 - Jul 5, 19:05 UTCJul 5, 20:15 UTC1h 10m
2026-07-05 SRR902 - Jul 5, 11:05 UTCJul 5, 16:15 UTC5h 10m
2026-07-04 SRR901 - Jul 4, 06:20 UTCJul 4, 10:10 UTC3h 50m
2026-07-03 SRR902 - Jul 3, 15:00 UTCJul 3, 16:10 UTC1h 10m
2026-07-03 SRR902 - Jul 3, 07:30 UTCJul 3, 12:45 UTC5h 15m
2026-07-02 SRR902 - Jul 2, 09:30 UTCJul 3, 08:40 UTC23h 10m
2026-07-02 SRR901 - Jul 2, 06:15 UTCJul 2, 10:00 UTC3h 45m
2026-07-01 SRR902 - Jul 1, 15:10 UTCJul 1, 16:25 UTC1h 15m
2026-07-01 SRR902 - Jul 1, 07:50 UTCJul 1, 13:00 UTC5h 10m
2026-06-30 SRR901 - Jun 30, 08:50 UTCJul 1, 08:45 UTC23h 55m
2026-06-30 SRR901 - Jun 30, 06:45 UTCJun 30, 10:40 UTC3h 55m
2026-06-29 SRR902 BHX → BLL Jun 29, 16:59 UTCJun 29, 18:14 UTC1h 15m
2026-06-29 SRR902 - Jun 29, 07:34 UTCJun 29, 12:24 UTC4h 50m
2026-06-28 SRR902 - Jun 28, 09:10 UTCJun 29, 08:44 UTC23h 35m
2026-06-28 SRR901 - Jun 28, 06:20 UTCJun 28, 10:15 UTC3h 55m
2026-06-27 SRR902 - Jun 27, 15:00 UTCJun 27, 16:10 UTC1h 10m
2026-06-27 SRR902 - Jun 27, 07:30 UTCJun 27, 12:34 UTC5h 5m
2026-06-26 SRR902 - Jun 26, 08:50 UTCJun 27, 08:44 UTC23h 55m
2026-06-26 SRR901 - Jun 26, 06:25 UTCJun 26, 10:20 UTC3h 55m
2026-06-25 SRR902 CVT → BLL Jun 25, 14:59 UTCJun 25, 16:09 UTC1h 10m
2026-06-25 SRR902 - Jun 25, 07:15 UTCJun 25, 12:19 UTC5h 5m
2026-06-24 SRR902 - Jun 24, 09:15 UTCJun 25, 08:30 UTC23h 15m
2026-06-24 SRR901 - Jun 24, 06:15 UTCJun 24, 10:10 UTC3h 55m
2026-06-23 SRR902 - Jun 23, 14:59 UTCJun 23, 16:09 UTC1h 10m
2026-06-23 SRR902 - Jun 23, 07:29 UTCJun 23, 12:40 UTC5h 10m
2026-06-22 SRR902 - Jun 22, 09:30 UTCJun 23, 08:45 UTC23h 15m
2026-06-22 SRR901 - Jun 22, 06:10 UTCJun 22, 10:00 UTC3h 50m
2026-06-21 SRR902 - Jun 21, 15:05 UTCJun 21, 16:10 UTC1h 5m
2026-06-21 SRR902 - Jun 21, 07:20 UTCJun 21, 12:24 UTC5h 5m
2026-06-20 SRR901 - Jun 20, 08:49 UTCJun 21, 08:40 UTC23h 50m
2026-06-20 SRR901 - Jun 20, 06:49 UTCJun 20, 10:39 UTC3h 50m
2026-06-19 SRR902 CVT → BLL Jun 19, 15:09 UTCJun 19, 16:14 UTC1h 5m
2026-06-19 SRR902 - Jun 19, 07:14 UTCJun 19, 12:19 UTC5h 5m
2026-06-18 SRR902 - Jun 18, 09:25 UTCJun 19, 08:29 UTC23h 4m
2026-06-18 SRR901 - Jun 18, 06:10 UTCJun 18, 10:00 UTC3h 50m

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-MAC page for operator, model, and routing details .

Mode-S 45B423 frequently asked

What is Mode-S code 45B423?
45B423 is an ICAO 24-bit transponder address. Allocated to Denmark. Assigned to OY-MAC.
Where is Mode-S 45B423 registered?
Mode-S code 45B423 is allocated to Denmark (DK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 45B423 broadcasting right now?
No active broadcast right now. Last signal was 17h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 45B423, octal 21332043, decimal 4,568,099.
What flights does 45B423 operate?
Mode-S 45B423 has broadcast 2 distinct callsigns, including SRR902, SRR901.