RAND, with the Ogden Air Logistics Center, examined maintenance procedures for the F-4 aircraft in support of the AF Maintenance Posture Improvement Program. The F-4 has been receiving maintenance on two independent schedules, one being a major calendar-based overhaul at a depot, the other being less drastic maintenance phased into six evenly spaced inspections and cyclically performed at the airbase every 450 flying hours. It was found that (1) certain minor inspections were unnecessary or unnecessarily frequent; (2) it was possible, with safety, to extend the base to 600 hours; and (3) many individual base inspections could be performed more efficiently during the dismantling at the depot. With all three steps implemented, it is estimated that, for the entire F-4 force, 1,537,500 maintenance man-hours (over 70 percent) per year would be saved. Furthermore, the number of aircraft tied up in the inspection docks on any given day would be reduced nearly 70 percent — from 129 to 41.