Lockheed Martin Corp., Lockheed Martin Aeronautics Co., Fort Worth, Texas, is being awarded a $4,011,919,310 fixed-price-incentive (firm target) (FPIF) modification to a previously awarded advance acquisition contract (N00019-10-C-0002).  This modification provides for the manufacture and delivery of 30 Low Rate Initial Production Lot V F-35 Joint Strike Fighter (JSF) Aircraft for the U.S. Air Force (21 Conventional Take Off and Landing (CTOL) aircraft); the U.S. Navy (6 Carrier Variant (CV) aircraft) and the U.S. Marine Corps (3 Short Take Off and Vertical Landing (STOVL) aircraft).  In addition, this modification provides for associated ancillary mission equipment and flight test instrumentation for those aircraft, and flight test instrumentation for the United Kingdom.  All effort will be contracted for on a FPIF basis, with the exception of work scope for the incorporation of certain specified concurrency changes that will be contracted for on a cost-sharing/no-fee basis.  Work will be performed in Fort Worth, Texas (67 percent); El Segundo, Calif. (14 percent); Warton, United Kingdom (9 percent); Orlando, Fla. (4 percent); Nashua, N.H. (3 percent); and Baltimore, Md. (3 percent), and is expected to be completed in January 2014.  Contract funds will not expire at the end of the current fiscal year.  This contract combines purchases for the U.S. Air Force ($2,644,270,340; 65.9 percent); the U.S. Navy ($937,374,286; 23.34 percent); the U.S. Marine Corps ($426,190,013; 10.6 percent); and the United Kingdom ($4,084,671; 0.1 percent).  The Naval Air Systems Command, Patuxent River, Md., is the contracting activity.