Ive quite recently done some engine courses and during morning Q +A session we got on to the subject of fuel burn influenced by taking air off the engines etc etc, this is easily understandable.
Then our instructor said that that if you use a bigger electrical load, say when you get icing conditions and your particular aircraft is fitted with leading edge electrical anti-icing blankets, the aircrafts fuel burn with no change in TLA, WILL increase.
So an extra load i.e anti-ice, nose cowl L/E being used will cause higher fuel burn, this surely cant be a significant amount ?
My question is, if so, why ?
I was under the impression, each IDG supplied 90 kva, and the galley will take 20 kva etc etc, but is it a problem with higher torque transmitted back through the engine from the IDG ? ive never been that bothered about this, im just interested. I can notice in cars sometimes, the RPM drops with higher electrical load used.