Analyzing air force flying-hour costs.

Introduction

We've all, at one time or another, walked into a room and flipped on the light switch, only to hear the pop of a light bulb going out. In terms of wear and tear, is leaving a light turned on day and night a quicker route to failure than turning the switch on and off excessively? The light bulb is a good example of certain components that are more likely to fail when being turned on and off than operating continuously. This phenomenon is known as failure on demand. When Headquarters Pacific Air Forces (PACAF) asked the Air Force Logistics Management Agency (AFLMA) to evaluate the idea of flying more F-15C/D sorties at reduced average sortie duration (ASD), failure on demand was just one of a variety of component failure modes considered. In less than 1 month's time, the AFLMA team illustrated not only the proposed sortie duration change's impact to the cost per flying hour (CPFH), but also how varied modes of failure influence the nature of aircraft breaks.

In the end, the study team would identify five ways in which aircraft and parts fail, as well as the effect varying sortie durations have on each failure mode. The analysis indicated that CPFH will increase as ASD decreases, irrespective of the amount of sorties or hours flown. The research and findings contributed to PACAF's design of the Kadena AB F-15C/D flying-hour program. The results proved to be both rapid and beneficial, including most notably an 18 percent improvement in the mission capable rate after just 2 months time.

Background

When the study team was first approached, Kadena AB was experiencing a higher number of F- 15 C/D maintenance issues than other F-15 C/D bases. For some time, mission capable (Me) rates had been approximately 20 percent lower than other F-15 C/D units, and Kadena AB had failed to meet any (all ten) Air Force F-15 C/D maintenance standards from May through June 2005. (l) With the intent of reducing an already heavy maintenance burden, Headquarters PACAF was considering the idea of reducing Kadena's F-15 C/D average sortie duration to reduce the overall number of flying hours accrued by each aircraft. However, PACAF maintenance leadership believed that reducing ASD would have a negative effect (increase) on the CPFH for Kadena' s F-15 C/D fleet. In the absence of any measurable data that directly addressed this claim, the study team would need to address the following items:

Define the CPFH model and the data used to compute hourly costs

* Identify Air Force maintenance metrics used to represent component failures

* Evaluate the factors contributing to component failure and reduced aircraft reliability

* Through statistical analysis, establish a lack of correlation between ASD and component failures

While the first three items could be accomplished through a review of existing literature and Air Force regulations, the last would require more extensive analysis. This analysis was necessary since illustrating a lack of …