Aim: To investigate the +Gz protection provided by tilt-back seat and GZ-2 anti-G suit.
Methods: 6 subjects were exposed to centrifuge and onset rate is 3 G/s. First, their relaxed +Gz tolerances were determined while using tilt-back seat of 13 degrees. Secondly, it was their +Gz tolerance provided by pressurized GZ-2 anti-G suit and tilt-back seat of 13 degrees. Finally, their +Gz tolerances while using pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees were determined. The difference between the first and the third result was the +Gz protection that pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees offered.
Results: +Gz protection of pressurized GZ-2 anti-G suit and tilt-back seat of 13 degrees was 3.06 G, and +Gz protection of pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees was 4.13 G, which had an increase of 1.06 G.
Conclusion: Tilt-back seat of 45 degrees can greatly enhance +Gz tolerances of human.