Using Sorties vs. Flying Hours to Predict Aircraft Spares Demand
Abstract
In Operation Desert Shield/Desert Storm, while tactical aircraft flew much longer sorties than planned, the demand for aircraft spares was substantially less than expected. The war plans were based on the standard assumption that spares demand is proportional to flying hours. Since wartime demand is predicted from peacetime data, and the peacetime training missions are mostly short sorties, it is critical to know whether spares demand is driven by the number of sorties, by flying hours, or by some combination. The U.S. Air Force has now accepted the results of our analysis, which show that demand is much more closely related to the number of sorties than it is to the number of flying hours. We recommended that the Air Force use a slope of about 10 percent, meaning that for each additional hour of sortie length after the initial hour, demands increase 10 percent. The data comprise over 700,000 sorties for 24 major aircraft types. The analysis controlled for a number of explanatory variables, including deferred maintenance, mission type, and location, as well as sortie length.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1997
- Accession Number
- ADA331910
Entities
People
- Craig C. Sherbrooke
Organizations
- LMI