The Air Force is removing and replacing 50 fasteners per jet in the area of cracks found on F-16D canopy sill longerons that the service says will temporarily restore the aircraft to flying status. Air Force spokeswoman Susan Murphy said Tuesday this temporary measure will be used on a case-by-case basis and each major command will determine if, and when, their respective aircraft will receive this repair. The Air Force July 31 discovered these cracks that eventually lead to the…