ship, the fact is no two ships are alike. For this reason, the Aviation Fuels Operational Sequencing System (AFOSS) was developed to provide each ship with tailor made correct written technical operating proce- dures for the equipment installed on that specific ship. Every fueling evolution performed by the ABF will have an AFOSS procedure and that procedure MUST be followed. AFOSS is developed into three operational stages. These stages are actually three copies of AFOSS designed around the purpose of each copy’s use. They are as follows: 1. The Division Officer’s copy 2. The Work center copy 3. The Work station copy The Division Officer’s copy contains the follow- ing: 1. 2. 3. 4. An index page. a. Assigns each fueling evolution a title and number. Step by step operating procedures for all evolu- tions concerning the fuels system. A liquid level status diagram. a. Lists all tanks by tank number. b. Shows relative location. c. Indicates each tank's designation. d. Gives the capacity of each tank. e. Provides a space to show the current amount of fuel in each tank. Training diagrams and charts. a. Shows each system. b. Indicates component locations. c. Gives the piping layout. d. Shows how different subsystems interrelate. The Division Officer’s copy is the master AFOSS for the division. It is used for training, scheduling and coordinating fueling evolutions, and insuring opera- tions are properly conducted. The work center copy is located in and applies only to a specific work center (flight or below decks) and contains the above information applicable to that work center only. The work station copy is located in and applies only to a specific work station (JP-5 filter, JP-5 pump room, lube oil pump room) and contains the above information applicable to that work station only. AFOSS operating procedures are prepared in a logical, detailed manner. They cover each fueling evolution and specific equipment used. They are also be used as a troubleshooting guide and as a reference for fuels casualty drills. The operations discussed on the following pages are for training purposes and are based on typical procedures used during those operations. The specific procedures for operations aboard a particular ship will be in that ship’s AFOSS. USE IT! SOUNDING TANKS While the tank level indicating equipment in use today is extremely reliable, the only 100% positive way to know how much and exactly what is in a tank is by sounding the tank. Sounding tanks is a simple procedure that has been used for as long as ships have sailed the sea. In the following paragraphs, we will discuss sounding equipment and procedures. Sounding Equipment Sounding tapes (fig. 4-49) are 50-foot steel tapes graduated in feet and inches (with the inches gradu- ated to 1/8 's). The bitter end is fitted with a snaphook for attaching a plumb bob or thief sampler. The first 9 inches of the tape consists of the plumb bob and snaphook. These tapes are usually plain, but can be ordered in color, such as black on white or white on black. Water-indicating and fuel-indicating pastes are available to assist in identifying positive “wet” marks on the tapes. Water-indicating paste will change color where the fuel/water interface occurs. Fuel-indicating paste will change color where the fuel/air interface occurs. There are two types of thief samplers (shown in fig. 4-50). These samplers may be made up locally or obtained from a naval repair activity. Both can be used in a standard 1 1/2-inch diameter sounding tube. Type A is used where it is not necessary to obtain a sample from the very bottom. Type B can be used (if rigged properly) for any level or bottom sampling. 4-60