Frequently Asked Questions - Ground Power Units


Q: Should I use ground power to start and service my single engined aircraft?

A: Ground power is recommended for all aircraft regardless of their size. Ground power should be utilised both during starting and servicing of the aircraft.


Q: What are the benefits of using ground power while starting my aircraft?

A: While an aircraft’s battery is capable of starting the engine/s or auxiliary power unit (APU), this function is not recommended on a recurring basis. The starting of an engine or APU puts an enormous strain on a battery and as such, shortens the life of the battery. Furthermore, if the battery is not sufficiently charged after starting, the battery will slowly deteriorate and may eventually fail. Perhaps most importantly, starting an engine with a less than fully charged battery may cause unnecessary engine wear and even damage.


Q: What are the benefits of using ground power while servicing my aircraft?

A: Aircraft batteries are not designed to be fully discharged and then recharged on a recurring basis. Using the battery while servicing the aircraft may lead to an over-discharged battery which in turn may lead to the battery being over-charged during the recharging process. Such over-discharging and corresponding over-charging may  damage the battery beyond repair.


Q: What type of ground power do I require for my aircraft?

A: The type of ground power required depends on the aircraft and on the application. A ground power unit required for starting an aircraft will require a higher current rating than one required for servicing of that aircraft. Ground power is typically either supplied as 28V DC or 115V 400Hz AC depending on the aircraft. If DC is required, either a battery powered ground power unit or a transformer rectifier unit should be used. Ideally, the transformer rectifier unit should be electronically controlled for safety reasons. If AC is required, static frequency converters should be used. 


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