Editing Bleed air (section)

===Benefits===
A bleedless aircraft achieves [[fuel efficiency]] by eliminating the process of compressing and decompressing air, and by reducing the aircraft's mass due to the removal of ducts, valves, heat exchangers, and other heavy equipment.<ref name="boeing">{{cite web | url=http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_07/article_02_1.html | title=787 No-Bleed Systems | publisher=Boeing | year=2008 | access-date=January 1, 2013 | author=Sinnett, Mike}}</ref>

The APU (auxiliary power unit) does not need to supply bleed air when the main engines are not operating. Aerodynamics are improved due to the lack of bleed air vent holes on the wings. By driving cabin air supply compressors at the minimum required speed, no energy wasting modulating valves are required. High-temperature, high-pressure [[air cycle machine]] (ACM) packs can be replaced with low temperature, low-pressure packs to increase efficiency. At cruise altitude, where most aircraft spend the majority of their time and burn the majority of their fuel, the ACM packs can be bypassed entirely, saving even more energy. Since no bleed air is taken from the engines for the cabin, the potential of engine oil contamination of the cabin air supply is eliminated.<ref name="boeing" />

Lastly, advocates of the design say it improves safety as heated air is confined to the engine pod, as opposed to being pumped through pipes and heat exchangers in the wing and near the cabin, where a leak could damage surrounding systems.<ref name="boeing" />