Aircraft electrics – how do we keep the lights (and everything else) on? | Aviation

Electrical systems are vital to modern passenger aircraft, powering everything from cockpit instruments to cabin lighting. The reliability and complexity of these systems ensure the smooth operation of an aircraft’s essential components. Let’s take a look at how a passenger jet’s electrical system works, using the Boeing 737-800 as an example. 

Which aircraft systems are electrically powered?

In short – a lot of them. Aircraft systems powered by electrical power include essential avionics like navigation and communication systems, flight control computers, and cockpit displays. Electrical power also supports cabin systems such as lighting, air conditioning, and in-flight entertainment. Additionally, electrically-driven hydraulic pumps help operate critical components like landing gear and flight control surfaces. So – an important system! But how does it work? 

How an Electrical System Works in jets

In the Boeing 737-800, the electrical system begins with engine-driven generators, but the process is more complex than simply producing power. Each of the aircraft’s two engines is connected to a generator that produces three-phase 115-volt AC power, but the challenge lies in ensuring a constant frequency, which is crucial for the stable operation of the aircraft’s electrical systems. This is achieved through a Constant Speed Drive (CSD) unit, a mechanical…