5-55. What total number of twists should be in a pigtail that is one-half-inch long? 1. Six to eight 2. Five to seven 3. Three to six 4. Four to five 5-56. Safety wire is installed properly if you observe which of the following actions? 1. The tension of the wire tends to tighten the bolt or nut 2. The tension of the wire tends to loosen the bolt or nut 3. The wire is as tight as possible 4. The wire has 5 turns per inch 5-57. What are the general classes of washers used in aircraft structures? 1. Plain, complex, and special 2. Plain, lock washer, and special 3. Castellated, castle, and plain 4. Castellated, lock, and plain 5-58. Lock washers are used with what type of nuts? 1. Castle 2. Plain hex 3. Elastic stop 4. Castellated shear 5-59. A star washer may be used what total number of times? 1. One 2. Two 3. Three 4. Four 5-60. What safetying device should be selected if it will be subjected to extreme heat and high vibration? 1. Cotter pins 2. Snap rings 3. Tab lock washers 4. Safety wire 5-61. Tab washers may be used what total number of times? 1. One 2. Two 3. Three 4. Four 5-62. What type of washers are widely used under AN hex nuts to provide a smooth bearing surface? 1. Special washers 2. Star lock washers 3. Plain washers 4. Tab lock washers 5-63. What class of washer is used under lock washers to prevent damage to surfaces of soft material? 1. Special 2. Castle 3. Complex 4. Plain 5-25