Date: 17 Dec 99 01:57:48 From: Erik Verheijden <firstname.lastname@example.org> Organization: @Home Network References: 1
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Jack Pease schreef: > > Don't suppose anyone can help me with a technie question. > > NOx emissions rise with engine power. NOx is saved if a pilot selects 85% > thrust on take off rather than 100% thrust, and presumably save fuel, so why > isn't this done all the time if the engines have enough in reserve??? Does > it reduce ambient noise if a plane shoots down the runway on 100% power then > thrusts down once over the airport boundary, or is it better to be 85% > thurst all the way but lower on the airport boundary? To answer part of your question, many take-offs are made at less than 100% (derating). The main reason for this is engine wear. A jet engine consumes much more fuel at lower altitudes. A take-off and climb with lower thrust settings may not save fuel at all: the airplane spends more time at low altitudes with a high fuel flow. Erik.