Figure 3-6 Five minutes less APU use per flight
3.2.4.3. ENGINE WARM-UP AND COOL-DOWN PERIODS
An engine from on an A320 Family aircraft
Reference documents
weighs approximately 1 ton and consequently
FCOM Volume 3 it takes time for all components to reach their Point of contact: fltops.perfo@airbus.com operating temperature. Furthermore the various components will expand and contract with temperature at difference rates. Minimum warm-up and cool-down periods have been determined to allow the engine to expand and contract in a more linear way and thus avoid unnecessary heavy or asymmetric rubbing. Such rubbing will increase running clearances that in turn will lead to losses in efficiency and increased fuel consumption.
3.2.4.4. SINGLE ENGINE TAXIING
At large or busy airports where the taxi time to and from the Reference documents
Getting to Grips with Fuel Economy – Issue 4 October 2004
runway can often exceed 15
FCOM Volume 3
minutes single engine taxi can
Point of contact: fltops.perfo@airbus.com
bring considerable benefits.
However, there are various factors that need to be considered before such a policy is implemented:
.
Engine start-up, warm up and cool down times must be respected.
.
Not suitable for high gross weights, uphill slopes or slippery runways.
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Not suitable for crowded ramps: due to reduction in aircraft maneuverability.
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Increased thrust setting on operational engine may increase ingestion of dust particles: refer to following section.
.
Mechanical problems may only become apparent after gate departure.
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On landing APU can be started before engine shutdown: avoids electrical transients and allows galley operation.
.
May increase tire wear and block time, but can reduce brake wear: through reduction in taxi speed.
Data - Mission A
$100,000 Annual cycles: 1800
Annual Flight Hours: 2700
$80,000 $) Average sector length (Hours): 1.5
US Additional fuel per sector (KGs): 58
$60,000 g ( Data - Mission B
Annual cycles: 1500 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：A320 Family performance retention and fuel savings(14)
