December 5, 2003 (by Lieven Dewitte) - The U.S. Air Force recently further extended the phase maintenance interval for its Block 40/42/50/52 F-16C/Ds to 400 flight hours. The F-16 now ties with the A-10 as the longest phase maintenance interval among all USAF combat aircraft.
The F-16 phase maintenance for this group of aircraft was extended from a single-phase inspection every 300 flight hours to one every 400 flight hours. This latest change is expected to cut the inspection workload nearly 20 percent. It also increases the number of aircraft available on the flight line for operational training or combat missions.
The USAF extension to 400 flight hours could have application for the international Block 40/50/52 operators, since many often follow the U.S. Air Force's lead in maintenance matters, and several are pursuing extensions of their particular F-16 phase intervals.
This change could potentially reduce the total base-level maintenance man- hours required to support these aircraft by five percent. These savings could equate to more than $1 million per year for the USAF fleet of Block 40/42/50/52 F-16s. Five major commands in USAF will be affected by this improvement.
The F-16 was originally fielded with an inspection cycle of four phases, one every 50 flight hours. The interval has been progressively increased to 100 hours, 150 hours, 200 hours, 300 hours and, currently, 400 hours. These increases were based on an extensive and recurring Reliability Centered Maintenance Analysis of USAF fleet aircraft maintenance data by Lockheed Martin engineers in a close teamwork approach with the customer.
Increasing knowledge and confidence in the aircraft, and reliability improvements have permitted these increases.
The F-16 airframe is designed so that no depot-level inspections are required during the 8,000-flight hour service life of the aircraft. Yet it does go to the depot on a periodic basis to get cetain items overhauled.
Phase inspections are conducted at the base level, either at home base or while deployed. Actions include inspecting the airframe and aircraft systems, replacing certain consumable items and fixing any discrepancies discovered. For convenience, special one-time, base-level inspections and parts changes are performed at this time. For active duty operations, a normal F-16 phase inspection takes about one week using a 10-person crew on two shifts.