perfect design thanks http://levitra-20-mg.in.net/ generic vardenafil "We have to understand what these pilots knew. We also need to look at how they were flying the airplane. Were they hand-flying the airplane? Were they relying on auto pilot or some combination of the two of those - and how those systems worked, if they worked as designed, if the crew understood what they were supposed to do," Hersman said in a CNN interview.