Sparrow Airlines is planning to reduce its costs by cleaning its planes' engines once a month, rather than the industry standard of every six months  With cleaner engines, Sparrow can postpone engine overhauls, which take planes out of service for up to 18 months  Furthermore, cleaning an engine reduces its fuel consumption by roughly 1
2 percent
the cost of monthly cleaning of an airplane's engines is not significantly greater in the long run than is the cost of an engine overhaul