AEROPLANE STARTERS
The first aeroplanes were started by pulling the propeller by hand, causing the crankshaft to turn. A few small propeller aircraft still start this way. But most propeller-driven light planes have an electric starter similar to those found in cars.
Most large commercial and military aeroplanes are equipped with an air turbine starter or a jet turbine starter. These small turbine engines bring the main jet engine up to normal operating speed by supplying it with high-pressure air. A separate auxiliary power unit (APU), located on the plane or on the ground, provides power for the starter.
