sensors Mode-S transponder

45AB28

ICAO 24-bit transponder address · allocated to Denmark

Currently assigned to OY-JYH · BOEING 737-800

Hex
45AB28
Octal
21325450
Decimal
4,565,800
Country
DK
Tail
OY-JYH
Type
B738
No current signal · last broadcast 14h ago
Flights observed
5
Distinct callsigns
3
Country
DK
Last broadcast
14h ago

Last known position

Most recent position reported by Mode-S 45AB28.

Country allocation

The ICAO 24-bit address 45AB28 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 3 distinct

Callsign Airline Flights Last seen
GRL774 Air Greenland 3 2026-04-13
GRL777 - 1 2026-04-12
GRL761 - 1 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 GRL761 - Apr 14, 08:05 UTCApr 14, 09:00 UTC55m
2026-04-13 GRL774 GOH → GOH Apr 13, 13:35 UTCApr 13, 14:50 UTC1h 15m
2026-04-13 GRL774 GOH → GOH Apr 13, 11:55 UTCApr 13, 14:50 UTC2h 55m
2026-04-13 GRL774 GOH → GOH Apr 13, 11:40 UTCApr 13, 12:15 UTC35m
2026-04-12 GRL777 - Apr 12, 17:15 UTCApr 12, 19:00 UTC1h 45m

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

Mode-S 45AB28 frequently asked

What is Mode-S code 45AB28?
45AB28 is an ICAO 24-bit transponder address. Allocated to Denmark. Assigned to OY-JYH.
Where is Mode-S 45AB28 registered?
Mode-S code 45AB28 is allocated to Denmark (DK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 45AB28 broadcasting right now?
No active broadcast right now. Last signal was 14h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 45AB28, octal 21325450, decimal 4,565,800.
What flights does 45AB28 operate?
Mode-S 45AB28 has broadcast 3 distinct callsigns, including GRL774, GRL777, GRL761.