Re: Engine start process questions

Date:         10 Jul 97 17:46:13 
From: (HatCat)
Organization: AOL
References:   1
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"There are no airliner jet engines that are started
electrically due to the excessive electrical loads that
would be required to spin such relatively large turbines."

Not absolutely true.  The BAE146/RJ series of airliners use electrical
start. The four Allied-Signal engines are small enough to be spun-up with
electrical motors. (in fact, the joke is that the plane is actually
equipped with five-APU's -- one in the tail and two under each wing!)

In this case the APU is for electrical power and air-conditioning, there
being no high pressure bleed to or from the engines. A battery start is
also possible as long as the aircraft is equipped with a dual battery
installation (optional) and the ambient air temperature isn't too cold
(affects battery performance).

The engines or APU can also be started off of a Ground Power Unit; either
115/220VAC at 400 Hz or a standard 28VDC hook-up.