Lockheed Martin Corp., Lockheed Martin Aeronautics Co., Fort Worth, Texas, is being awarded a $4,123,746,486 modification to a previously awarded fixed-price-incentive firm-target contract (N00019-13-C-0008) for the production of 43 Low Rate Initial Production (LRIP) Lot VIII F-35 Lightning II aircraft. This includes manufacture and delivery of 29 F-35A aircraft for the U. S. Air Force (19), government of Italy (two), government of Norway (two), government of Japan (four) and government of Israel (two). In addition, this modification provides for 10 F-35B aircraft for the U.S. Marine Corps (six) and government of the United Kingdom (four); and four F-35C aircraft for the U.S. Navy (three) and U.S. Marine Corps (one). This modification also provides for LRIP Lot VIII production requirements, including diminishing manufacturing sources redesign and management, ancillary mission equipment, including pilot flight equipment, and concurrency changes to LRIP Lot VIII aircraft. Work will be performed in Fort Worth, Texas (55 percent); El Segundo, California (15 percent); Warton, United Kingdom (10 percent); Orlando, Florida (5 percent); Nashua, New Hampshire (5 percent); Baltimore, Maryland (5 percent); and Cameri, Italy (5 percent), and is expected to be completed in May 2017. Fiscal 2014 aircraft procurement funds (Air Force, Marine Corps and Navy), international partner funds, and foreign military sales funds in the amount of $4,120,352,986, will be obligated at the time of this award, none of which will expire at the end of the current fiscal year. This contract combines purchases for the Air Force ($1,701,415,744; 41 percent); Marine Corps ($583,570,317; 14 percent); Navy ($491,755,261; 12 percent); international partners ($786,460,233; 19 percent); and foreign military sales ($557,151,431; 14 percent). The Naval Air Systems Command, Patuxent River, Maryland, is the contracting authority.