The Air Force is budgeting to spend $29.5 billion on all aspects of the Joint Strike Fighter over the next five years, including about $1 billion to pay for concurrency changes to early production aircraft. In its fiscal year 2013 budget request released this week, the Air Force announced it would slow its F-35 procurement rate, delaying the purchase of 98 F-35 aircraft into the future and saving money in the short term. But budget documents show that the service...