[NTG-context] Rotating multiple-page spanning tabulate

Hi, I have a tabulate which spans multiple pages and is broader than \textwidth, but slightly smaller than \textheight. I therefore want to print it 90 degrees rotated, but it still should span several pages and the headertexts should remain at the old place. Any idea how to do this? If this is not possible, what is the best way to temporarily switch to landscape? Tobias