Then came the acrobatics. It was the same as the L39 but six G's instead of 
 four G's and 4000 meters altitude instead of 2000 meters. At this time I realized 
 that the ground crew had not connected my G suit to the pneumatics in the
 plane. At the bottom of every loop, my vision went from color to
 black-and-white. It happened in about a second like someone pulled down a
 no-color shade in front of my face. Shortly after that, the
 black-and-white
 faded into grey-and-grey and finally just grey. Very strange feeling.
 I didn't black out but I was able to know exactly what it would feel like.
 After the G's subsided, my vision returned in reverse sequence.