On June 11, 2010, several environmental interest groups filed a complaint in the U.S. District Court for the District of Columbia challenging the U.S. Environmental Protection Agency’s (EPA) failure to implement rules on greenhouse gas emissions by aircraft and other mobile sources.  Plaintiffs filed a petition in December 2007 requesting that EPA adopt and implement regulations on GHG emissions from aircraft.  Plaintiffs allege that EPA’s failure to respond to the petitions violates the Clean Air Act and request that the court direct EPA to issue findings and, if warranted based upon those findings, initiate rulemaking to establish limits on emissions.