+ 60 - 60 -30 +30 0 A M P Heavy current to starter 24 Volts  DC input 24 Volts  DC input Starter vibrator Ground through switch actuates battery solenoid Auxiliary voltage input Heavy current to starter Solenoid actuating voltage Solenoid actuating voltage External power receptacle Left magnetos Circuit breaker Starter switch left Left engine starter Left starter solenoid Battery solenoid Battery switch Right engine starter Right starter solenoid Ammeter shunt  BUS Starter switch right Right magnetos Figure 5-5.  Engine starting schematic for a light twin-engine aircraft.  with the load. The starter gear section consists of an external  housing with an integral mounting flange, planetary gear  reduction, a sun and integral gear assembly, a torque-limiting  clutch, and a jaw and cone assembly.  [Figure 5-6]  When the  starter circuit is closed, the torque developed in the starter  motor is transmitted to the starter jaw through the reduction  gear train and clutch. The starter gear train converts the high  speed low torque of the motor to the low speed high torque  required to crank the engine. In the gear section, the motor  pinion engages the gear on the intermediate countershaft.  [Figure 5-6]  The pinion of the countershaft engages the  internal gear. The internal gear is an integral part of the sun  gear assembly and is rigidly attached to the sun gear shaft.  The sun gear drives three planet gears that are part of the  planetary gear assembly. The individual planet gear shafts  are supported by the planetary carrying arm, a barrel-like  part shown in  Figure 5-6 .  The three planet gears also engage the surrounding internal  teeth on the six steel clutch plates.  [Figure 5-6]  These plates  are interleaved with externally splined bronze clutch plates  that engage the sides of the housing, preventing them from  turning. The proper pressure is maintained upon the clutch  pack by a clutch spring retainer assembly. A cylindrical  traveling nut inside the starter jaw extends and retracts the  jaw. Spiral jaw-engaging splines around the inner wall of the  nut mate with similar splines cut on an extension of the sun  gear shaft.  [Figure 5-6] The carrying arm transmits torque from the planet gears to  the starter jaw as follows: 5-4 3.  The jaw slides fore and aft inside the carrying arm to  engage and disengage with the engine. 2.  Mating splines are cut on the exterior surface of the  cylindrical part of the starter jaw. 1.  The cylindrical portion of the carrying arm is splined  longitudinally around the inner surface.