Increase Repair Capability

Case_4_F-16_Pylon.pdf

Problem

The F-16 Fighting Falcon is the mainstay of tactical aviation within the U.S. Air Force. It is a supersonic, single-engine all-weather-capable air superiority fighter is also used in ground attack roles. The F-16 is made in both single-seat and dual-seat variants. Of particular interest regarding this case study, the F-16 has several weapon and equipment attachment points on its wings that are known as pylons. (See Figure 9.) Proper operation of these pylons is essential for accurate delivery of weapons. The Air Force is currently operating a fleet of more than 1,200 F-16 aircraft.

Figure 9. The F-16 Fighting Falcon is the mainstay of U.S. Air Force tactical aviation. The structures under the wings are known as pylons and are used to attach missiles, bombs and various other equipment to the aircraft.

The U.S. Air Force Ogden Air Logistics Center (ALC) is located at Hill Air Force Base, Utah. It is the primary depot responsible for overhauling and repairing the F-16’s aircraft wing pylons.  The Ogden depot was facing challenges in meeting its workload requirements due to high repair cycle times and poor on -time delivery.  The impact of these problems was causing airmen in the field to cannibalize pylons (taking from one aircraft to install on another); thereby causing multiple maintenance actions and driving up cost and risk. Due to the large size of the F-16 fleet, this was a problem that could not be ignored.

Approach

To address these problems, the Ogden maintainers had to discover what was driving the long cycle   times and come up with solutions. After thorough analysis using Lean Six Sigma tools called value stream maps and spaghetti diagrams, the team was able to visually see where the waste in the process was located and find ways to reorganize the shop floor to eliminate the waste and improve the speed and quality of the pylon repairs. The team found waste in many areas including transportation, motion, overproduction and wait- time of mechanics.  The team then used Lean principals to develop a cellular workflow that co-located the process steps with the equipment and supplies needed to perform each step. This rearrangement shortened the motion and transportation time within the shop and coupled with changes in workflow, this made dramatic improvements in the flow time. It also reduced defects and rework.

Results

The team accomplished significant waste elimination which decreased the pylon’s repair cycle time from 146 days to 18 days – an 88% reduction!  The elimination of waste also resulted in a faster process that helped eliminate 350 back-ordered pylons, and reduced the number of pylon’s sitting at the depot by 75%.  Eliminating the waste also revealed excess capacity in terms of both floor space and labor that enabled the shop to take on new, additional work.  Using the excess capacity, the pylon shop now repairs and overhauls wing pylons for the A-10 Thunderbolt in addition to the F-16. For both aircraft, 100% on-time delivery to the warfighter is being achieved.   These accomplishments are illustrated in Figure 10.