We'll need to take up references <a href=" http://www.spacecake.co.uk/olanzapine-crazy-meds.pdf ">zyprexa tablets</a> Hersman said on CBS' "Face the Nation" Sunday that the glide slope system is a ground-based aid that helps pilots stay on course while landing and it has been shut down at the San Francisco airport since June. The pilots, however, were notified before the crash that the system wasn't available.