Aircraft Electrical Systems Which of the following are the major parts of a DC motor? 1. Armature assembly. 2. Field assembly. 3. Brush assembly. 4. Commutator. 5. Pole piece. 6. Rheostat. 7. End frame. a. 1, 2, 3, 7. b. 2, 3, 4, 5. c. 3, 5, 6, 7.