ANTI-G GARMENTS

Figure 4-9.—Fitting the SRU-25/P rubber socks. top of the folded socks (fig. 4-9). Have the aircrew member take off the coveralls. Remove the top 2 inches of the socks with a pair of sharp scissors. 5. Remove excess material from the coverall leg by cutting a line 1 inch below the mark that was applied in step 4. Ensure the leg is cut perpendicular to the lengthwise direction of the leg. Make your alignment marks at the front of the coverall legs and socks to ensure the socks will be properly aligned with the legs during the attachment process. 6. Turn the coveralls inside out and lay them flat, facing up. NOTE: When you attach the socks to the coveralls, the right sock is on the right leg and the left sock is on the left leg. 7. Insert the sock into the leg opening, so that the right sides of the sock and coverall leg are facing each other, and the toe is pointing up (toward the front) (fig. 4-10). Figure 4-10.—Attaching the rubber sock to the coverall leg. 8. Beginning at the front of the leg, make sure the alignment marks are matched. Then attach the sock with one row of stitches, one- fourth inch from the cut edges, five to seven stitches per inch, using nylon size E thread. Overlap the stitching one-half inch. Do not backstitch. 9. Fold the cut edges of the seam over the sock. Make the fold as near the stitch line as possible. Apply one layer of 1 1/2-inch seam tape over the seam, keeping the stitch line and the cut edges as nearly centered under the tape as possible. Overlap the ends of the seam tape 1 inch. 10. Additional information on maintenance procedures, inspection cycles, and test equipment for antiexposure assemblies is covered in the Aircrew Personal Protective Equipment Manual, NAVAIR 13-1-6.7. ANTI-G GARMENTS Although there is no limit to the speed a human can endure in straight and level flight in an aircraft, changing speed or direction can produce inertia to which the body has a sharply limited tolerance. In the case of extreme stresses exerted by forces of the type met in seat ejection, ditching, or parachute opening shock, the short duration of the force restricts its effects. However, changing the direction of flight often produces stress forces equal to several times the normal value of gravity for periods longer than a second. These forces can have dangerous effects. At 5 g’s (five times the force of gravity), the pilot’s body is exposed to a force that increases its weight and that of its components five times. This increased weight has many effects. The pilot is pushed down into his seat. His arms and legs feel like lead, and manipulation of the controls becomes more difficult. In addition, the extra weight of the internal organs causes abdominal and chest discomfort. Most important, however, is the effect on the circulatory system. At 5 g’s the pressure exerted by the column of blood between the head and the heart becomes just about equal to the blood pressure in the arteries. As a result, the pressure supplied by the heart is not great enough to pump an adequate supply of blood to the head. To counteract these effects, the pressure in the arteries must be increased above the heart level. At the same time, distended vessels and tissue and fluid spaces in the regions below the heart must 4-2