(Editor's Note: This story has been updated to reflect that the Air Force's light-attack aircraft effort will be funded in fiscal year 2017 using more than $4 million in research, development, test and evaluation money, though the cost will change based on how many aircraft participate.) ORLANDO, FL -- Air Force Chief of Staff Gen. David Goldfein told reporters Friday he will green-light an experiment this week to explore and test light-attack aircraft this summer at Holloman Air Force...