T = Time in seconds D = GGF (distance) S = Ground speed in feet per second By substituting the values, you can determine the exposure intervals as follows: 3600 T = 212.5 or 16.9 seconds for aircraft flying toward the north 3600 T= 263.5 or 13.6 seconds for aircrafr flying toward the south 6. Graphic scale. To determine what graphic scale represents  3,000  feet,  you  should  use  the  IFGA  formula as follows: _I=FG A I =^{12 3000}= 3 inches 12,000 Therefore, 3 inches on the map represents 3,000 feet on the ground. SAFETY Whether you take photographs from the rear seat of a jet or from the open door of a helicopter, you must be checked out and become thoroughly familiar with the necessary safety equipment and applicable safety procedures. Before the flight, you should arrive at the aircraft  or  briefing  area  in  sufficient  time  for  the preflight brief. The main responsibility of the pilot is to fly you and your photographic equipment to the target, put the aircraft in position for photographing, and return to the base safely. The pilot knows the limitations of the aircraft and what procedures to follow in an emergency.  Ask  the  pilot  about  emergency  plans  and FOLLOW this advice. Aircrew  personal  protective  equipment  plays  an essential role in the safety and survival of people flying in Navy aircraft. The equipment is designed to protect them from the elements and to provide necessary comfort for efficient mission performance. Its primary function  is  to  protect  a  crew  member  against  the environmental hazards. Different combinations of clothing  and  equipment  are  used  to  provide  overall protection and comfort to an air crew member under various   flight,   emergency,   and   environmental conditions. Aircrew protective equipment is designed to meet the stress of a combat environment and to provide fire protection  and  camouflage  with  various  other  escape and  evasion  design  features.  Emphasis  is  placed  on developing  materials  and  clothing  assemblies  to enhance an individual’s chance of survival and to minimize injuries in an aircraft accident. Before flying in an aircraft, you must obtain the proper personal protective equipment specified for the type  of  aircraft  in  which  you  will  be  flying.  The squadron-,  intermediate-,  or  depot-level  maintenance activities  can  provide  you  with  the  required  equipment. YOU MUST NOT FLY WITHOUT THE PROPER EQUIPMENT and the equipment must fit you correctly. Your life may depend on it. WARNING Unauthorized modification or deviation from prescribed life support and survival equipment by individual crew members could  create  safety  hazards.  NATOPS General  Flight  and  Operating  Instructions, OPNAVINST  3710.7,  specifies  minimum requirements for such equipment and is supplemented by the naval air training and operating    procedures    standardization program  for  each  specific  model  of  aircraft. Peculiar configurations or modifications to life support and survival equipment are not authorized.  Aircrew  Survival  Equipment- man (PR) who issue and maintain this equipment   have   no   authority   or responsibility to perform these actions, so do not ask them to do so. During takeoffs and landings, your photo gear must be made secure within the aircraft, so it does not become a hazard. When your equipment consists of small items, such as a hand-held camera and exposure meter, hold them in your lap. Tie-down straps or passenger seat belts provide a means of securing bulky equipment. If you cannot find the means to secure your equipment on board the aircraft, request assistance from the plane captain or another crew member. During flights in a helicopter, keep all photo gear secure. This will prevent it from falling out an open door. It is a violation of federal law to drop objects from aircraft while in flight. When working in or leaning out of an open door or window in an aircraft, you should use a neck strap or wrist strap to secure your camera and other items. 4-26