You're welcome :). My native language is not English either. So I guess we think in the same way when trying to say something in English ;)

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I think his can happen for two reasons. codered has mentioned one of them. You may be hitting the runway hard. To check, disable the crash option in the realism settings and try to land.
If this is not the case then you may be having problem with the scenery or the airport. In this case you may need to alter some numbers in some cfg files. But I don't know this kind of stuff well.
I'm sure someone else will explain it to you, once the problem is determined.