According to DOD: United Technologies Corp., Pratt & Whitney Military Engines, East Hartford, Conn., is being awarded a $508,214,419 modification to the previously awarded F-35 Lightening II Lot VI low rate initial production advance acquisition contract (N00019-12-C-0090). This modification provides for the procurement of 18 F135 conventional take off and landing (CTOL) propulsion systems for the U.S. Air Force; six short take-off and vertical landing propulsion systems for the U.S. Marine Corps; and seven carrier variant propulsion systems for the U.S. Navy. In addition, this contract procures three F135 CTOL propulsion systems for Italy; two CTOL propulsion systems for Australia; one F135 CTOL spare propulsion system for Italy; and one F135 spare propulsion system for Australia. This modification also provides for program labor, engineering assistance to production, non-recurring sustainment efforts, service and country specific requirements, depot activation efforts, and long-lead hardware. Work will be performed in East Hartford, Conn. (67 percent); Bristol, United Kingdom (16.5 percent); and Indianapolis, Ind. (16.5 percent), and is expected to be completed in June 2016. Fiscal 2012, aircraft procurement Air Force, fiscal 2012 aircraft procurement Navy, and international partner funding in the amount of $508,214,419 will be obligated at time of award, $422,680,150 of which will expire at the end of the current fiscal year. This contract combines purchases for the U.S. Navy and Marine Corps ($211,858,131; 42 percent); the U.S. Air Force ($210,822,019; 41 percent); and the international partners ($85,534,269; 17 percent). The Naval Air Systems Command, Patuxent River, Md., is the contracting activity.