Introduction Most aircraft engines, reciprocating or turbine, require help  during the starting process. Hence, this device is termed the  starter. A starter is an electromechanical mechanism capable  of developing large amounts of mechanical energy that can  be applied to an engine, causing it to rotate. Reciprocating  engines need only to be turned through at a relatively slow  speed until the engine starts and turns on its own. Once  the reciprocating engine has fired and started, the starter is  disengaged and has no further function until the next start. In  the case of a turbine engine, the starter must turn the engine  up to a speed that provides enough airflow through the engine  for fuel to be ignited. Then, the starter must continue to help  the engine accelerate to a self-sustaining speed. Turbine  engine starters have a critical role in starting of the engine.  Chapter 5 Engine Starting Systems