Anytime it comes to powering an aircraft, there are two main sources; external power and onboard power.  The external power comes from a Ground Power Unit, or GPU for short, that is generally used in the hangar for powering things such as the lights and other avionics on the aircraft.  The onboard power comes from the APU, or Auxiliary Power Unit, which is actually installed in the aircraft and is therefore is not mobile like the Ground Power Unit can be.  This is just the main difference between Ground Power Units and Auxiliary Power Units, but we can go into much more detail when comparing the capabilities and uses of the two power sources.

How Are Ground Power Units Used?

As we said before, Ground Power Units are the external power source for aircrafts when they are in the hangar, GPU aircraft.  But, how do they operate to power the aircraft?  Typically, Ground Power Units are either diesel fueled or building mounted.  In the case of diesel fueled GPU’s, these are usually portable units that you will often see as portable carts that come to the front of the aircraft after it is parked.  On the other hand, building mounted GPU’s are most often found on the jet bridge.  After the aircraft is parked, a cable is lowered from bridge and used to plug into the aircraft and power it.  As far as when Ground Power Units should be used, they are most often used in military and civilian aircraft situations due to their ability to supply and stable and prepared amount of energy. 

How Are Auxiliary Power Units Used?

Auxiliary Power Units, or APU’s, are the standard onboard power source for aircrafts.  APU’s cannot be run indoors, therefore they can’t be used inside the hangar as they are designed to be operated within the aircraft to power it when it cannot be connected to a Ground Power Unit.  The avionics, such as flight data recorders, weather radars, and any other electronic system specifically designed for use in aviation are all usually powered using Auxiliary Power Units. 

It is important to note that not one method is not superior to the other, both of these power units work hand in hand to power the aircraft.  While GPU’s power the aircraft on land, the APU’s power the aircraft in the air making it so that not one can function without the other helping to keep everything in balance. If you have any further questions about GPU aircraft or portable GPU for aircraft or questions about the types of Ground Power Units that Powerall Systems is able to provide for you're aviation needs, don’t hesitate to reach out today!