REVIEW QUESTIONS

Figure 1-40.—Survivability of a person in water. Anti-immersion suits are worn by aircrew personnel to retain body heat if the aircrew must ditch in the water. Unfortunately, anti-immersion gear is bulky and hot, and aircrews prefer not to wear the gear. When environmental conditions indicate usage is required, shipboard Aerographers routinely include in flight weather briefings the recommendation that aircrews use anti-immersion suits. This recommendation should also be included in shore-station briefings for over- water flights. Navy and Marine Corps observers usually provide the necessary information to the briefer, based on their observations of the environmental conditions. Guidance for anti-immersion suit usage by aircrews is given in OPNAVTNST 3710.7, NATOPS General Flight and Operating Instructions. Anti-immersion suits or pressure suits with thermal undergarments must be worn when the coldest water temperature in the mission area is � 50°F or if the coldest wind chill equivalent temperature on the (water) surface during the mission is � 32°F. When the water temperature is >50°F but � 60°F, antiexposure undergarments must be worn, but the determination to wear anti-immersion suits is made by the commanding officer. His or her determination should be based on the length of time required to respond with rescue assets to a ditch site, ranging from 1 hour at 50°F to 3 hours at 60°F. With water temperatures above 60°F, anti-immersion gear is not required. Navy and Marine Corps weather observers routinely provide various values and indicators that are used to gauge the effects of hot and cold environments on personnel. These values are computed from observed measurements made during surface weather observations. All observers should be aware of the effects of heat and cold on the human body, and should be able to calculate the various indicators upon request. Weather affects the performance of equipment as well as personnel. In the next section, we consider aircraft performance in changing weather conditions. Q86. Q87. Q88. Q89. Q90. Q91. REVIEW QUESTIONS What term describes the inability of the body to get rid of excess heat fast enough to maintain an internal temperature balance? Define the term "relative humidity." Given an air temperature of 90°F and a relative humidity of 65%, what is the apparent temperature? What effects does the Wet-bulb Globe Temperature index (WBGT) take into consideration? What is meant by the term "wind chill factor"? What is the survival chance given a seawater temperature of 15°C and an immersion time of 3 hours. 1-59