With practice a pilot can withstand 5-6G’s by flexing the muscles of the legs and abdomen to prevent blood from accumulating there. During this flight however, the aircraft was only tested at 7Gs of acceleration even though it is capable of performing manoeuvres at 9Gs. The F16 is a relatively old plane that was designed in the 1970’s and this development means that it might in future be possible to replace fighter pilots with unmanned planes (drones) that can perform much more demanding high acceleration manoeuvres that cannot be performed by the best fighter pilots. For more detail and video: http://www.gizmag.com/boeing-f16-jet-unmanned-drone/29203/