How Are Aircraft Engines Started
Gas turbine engines and reciprocating engines are technological marvels, allowing small and large aircraft to efficiently travel across the globe. Unlike the engine of an automobile or an early aircraft, the starting process for a modern aircraft engine is much more complex and may require multiple equipment pieces to be carried out. As engine assemblies are paramount to the capability of flight, it can be extremely beneficial to understand how the engine starting process works as well as what systems are involved in order to ensure proper functionality.
One of the most important elements of the aircraft engine starting process is the starter, that of which regularly comes in the form of an electromechanical mechanism that is used to produce enough mechanical energy to begin engine rotation. For a piston engine, only a slow speed is needed for the engine to begin its own functions. Once the piston engine begins firing, the starter can be disengaged and will remain unused until the next start. With gas turbine engines, on the other hand, the starter will often be used to speed up the engine until it reaches a sufficient RPM for airflow and fuel ignition.
For turbine engines in particular, the direct cranking electrical system and starter generator system are both used to initiate engine operations. While the direct cranking system is most popular for small turbine engines such as an auxiliary power unit (APU), starter generators can serve a large variety of engines. The functionality of the direct cranking system and starter generator system is quite similar, though their difference lies in the fact that the starter generator will initiate turbine engine operations and then switch to acting as a generator once the engine has reached a speed that is self-sustaining. In order for the starter generator to perform its role, it is attached to the main shaft of the engine with drive gears. With a series winding that is electrical connected, a strong magnetic field can be formed within the starter generator in order to produce the torque needed for starting. As the starter generator can fulfill both the role of starting the engine and powering the aircraft electrical system, they are highly desirable for optimizing the weight of an aircraft.
While many early reciprocating or piston engines were manually started by hand as pilots pulled on the propeller, a number of piston engine aircraft now rely on more advanced starting systems such as the direct cranking electric starter. As the most widely used system currently, the direct cranking electric starter offers instant and continual cranking when energized. Direct cranking electric starters consist of a number of components, the most important being an electric motor, reduction gears, and an automatic engaging and disengaging device. Depending on whether the piston engine is small or large, the direct cranking electric starting system may vary slightly in its makeup to ensure that proper torque and energy is provided to start the engine.
Despite the direct cranking electric type starter being the most widely used method for reciprocating engines, some still rely on older methods such as inertia starters. Inertia starters may be hand powered, electrical powered, or a combination of the two. Through either manual or electrical means, the inertia starter allows for energy to be stored up in the device as the system is cranked. Once the device is fully energized, it can transfer the energy to the engine itself in order to initiate operations.
With any of the starting systems that serve aircraft engines, it is important that they are well maintained as to ensure their proper functionality and health. At Limitless Aerospace, we serve as an online distributor of aircraft parts with over 2 billion items readily available for purchase through our website. The quality of our offered items is of the utmost importance to us, and we ensure that every part and component has been sourced from a trusted manufacturer and has undergone rigorous quality assurance testing and inspection prior to shipment. Due to our steadfast commitment to such practices, we are proud to operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation. Begin the purchasing process today and see why customers choose to rely on Limitless Aerospace for all their operational requirements.
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