Well, even during WWII pilots were given benzedrine routinely
http://en.wikipedia.org/wiki/Benzedrine
TIME 14th sept 1942 ;
The Air Surgeon's office last week called benzedrine the best drug "for temporarily postponing sleep when desire for sleep endangers the security of a mission." Times to use benzedrine: when a pilot cannot...
Source :
http://www.time.com/time/magazine/ar...#ixzz1nxe3dnCd