4-58. The fuselage of the H-60 helicopter is of what type of construction? 1. Graphite monocoque 2. All–metal semimonocoque 3. Reinforced carbon shell 4. Welded steel truss 4-59. What type of main landing gear is mounted on the H–60 helicopter? 1. Retractable 2. Fixed–skid type 3. Nonretractable 4. Conventional fixed 4-60. What   assembly   provides   attachment   of   the main rotor blade to the rotor hub? 1. Cuff 2. Spar 3. Root end 4. Tip cap 4-61. The hub and swashplate of a helicopter are the principal components of what unit(s)? 1. Tail rotor 2. Droop restrainers 3. Rotary head 4. Antiflapping restrainers 4-62. The   movements   of   the   flight   controls   are transmitted to the rotary wing by the action of what components? 1. Hinges and rotating scissors 2. Sleeve spindles and antiflapping restrainers 3. Damper positioners and stationary scissors 4. Hydraulic servo cylinders, swashplate, and pitch control rods 4-63. Change in rotary rudder head pitch is increased as  the  pitch  change  shaft  is  moved  in  what direction? 1. Up 2. Down 3. Inward 4. Outward 4-64. The     efficiency     of     hydraulic     operation     is approximately what percent? 1. 100% 2. 95% 3. 85% 4. 75% 4-65. Which of the following is a disadvantage of the hydraulic system as a power source for aircraft control units? 1. Extensive maintenance requirements 2. Possibility of internal and external leakage 3. Loss of efficiency due to friction 4. Heavy weight IN    ANSWERING    QUESTIONS    4-66    THROUGH 4-68, REFER TO FIGURE 4-22 IN THE TEXT. 4-66. What   component   is   often   referred   to   as   an unloading valve? 1. Pressure regulator 2. Check valve 3. Selector valve 4. Actuating unit 4-67. What component maintains an even pressure in the hydraulic system and acts as an emergency source for operating certain actuating units? 1. Power pump 2. Accumulator 3. Pressure gauge 4. Selector valve 4-68. Check valves are used in a hydraulic system for what purpose? 1. To bleed off pressure 2. To stop the flow of fluid 3. To allow one direction of flow only 4. To bypass filter element 4-69. Foreign material in the hydraulic system of an aircraft is defined as hydraulic contamination. 1. True 2. False 4-70. What source of hydraulic contamination usually causes the most trouble? 1. Poor servicing 2. Self-generated 3. Normal wear 4. Manufactured 4-71. Which  of  the  following  rules  is/are  basic  to aircraft hydraulic servicing? 1. Never use fluid from a container that has been left open 2. Use only approved servicing units 3. Always maintain a high state of cleanliness 4. All of the above 4-27