Aircraft Planned Inspection Policies

Briefly summarizes to late 1970 RAND's findings concerning aircraft inspection intervals and content at base and depot levels. In 1966, the Military Airlift Command switched from a flying hour inspection of their C-141s to an isochronal or calendar time inspection at base level. This allowed a team of investigators to study the effects that variable flying hours have on aircraft. They found that between inspections, aircraft with many flying hours appeared to perform no differently on maintenance and operations measures than aircraft with fewer flying hours. Studies at depot level were made of the F-106, as described in R-755, and of the F-4 which are also on the isochronal system. Findings were similar to those for the C-141. These data suggested that some aircraft inspection intervals could be safely extended, and in some instances this has already begun. RAND and the Air Force Logistics Command are continuing these investigations.