Why is Emirates making a stop at CPH?

[Jccl]

I have been wondering about a thing for some time now and I hoped someone at this forum could help me with an answer.
Almost every day there are 1-3 Emirates from Dubai, on its way to the US, that make a stop at CPH. I guess Cargo could be one explanation but the flights are not registered as cargo. It also doesn't look like they are doing a detour so they must stop and fill up. Any ideas why?

[Someone]

It is mainly Cargo, usually «Preighters»

Notice A6-EGG is there now, flying Dubai-Copenhagen-Columbus, as a cargo only flight

EK2xxx flightnumbers usually mean a cargo only flight

[Jccl]

I knew I could get an answer, informative and quick. Now I have learned "preighters" and how to interpret the flight numbers. Great and thank you very much :-)

[Someone]

The reason for the stop is due to crew change

[Jccl]

I am sorry Someone but here is one more... Why crew change in CPH? They didn't do this before and I guess you dont need to change crew on a flight from Dubai to a US destination. I thought Dubai was their only base with that staff.

I am of course fishing a little bit for the answer that they have expanded in one way or another, but understand its probably just a practical thing :-)