What component of an aircraft generates its electric power?
For most small planes, it is the battery, which turns the electric starter motor. A generator driven by the engine or by a small propeller in the slipstream then charges up the battery while the plane is flying.
Some history:
a few older and small planes had a pull cord in the cockpit with which the pilot could pull-start the engine, like a lawn mower. For engines with no starter at all, the pilot or their assistant would grab the propeller and swing it around by muscle power to start the engine (be careful!).
Some very old planes had starters operated by a crank that you stuck into a hole in the engine cowling, and turned by arm power. This worked for small engines but was too hard to do for bigger engines. In that case, the crank turned a small flywheel up to great speed and then the engine was geared into the flywheel through a reduction gear drive, and the energy stored in the rotating flywheel turned the engine to start it. This was used in the P-26 &quot;Peashooter&quot; plane.
In later years, a small electric motor spun the flywheel up to speed instead of a hand crank. The Antonov An-2 still uses this type of starter, called an inertia starter, as does the Dromader crop duster with the radial engine.
Another method of starting an airplane engine was to explode a blank shotgun shell in a closed chamber and send the hot gas through a tube to a special cylinder geared onto the crankshaft, which thereby turned the crankshaft to start the engine. This is called a Coffman starter and it plays a key role in the old movie &quot;The Flight Of The Phoenix&quot;. In some versions of this principle, the gases from the shotgun shell were sent right into one of the cylinders of the engine itself, forcing the piston down and turning the crankshaft.
This idea saw use in more modern times, where a jet engine could be started by burning a charge of solid rocket motor fuel called a cartridge inside a sealed chamber and using the hot gas to spin up the exhaust turbine. F-4 Phantom jet fighters could be started with cartridges like this in just a few minutes even in Alaskan winters- without the use of a start cart.