Expeditionary Operations: intermediate engine maintenance alternatives

Air Force Journal of Logistics, Spring, 2001 by Mahyar A. Amouzegar, Lionel Galway, Amanda Geller, Robert S. Tripp, Clifford Grammich

Transportation Requirement for F100 Engines

It is somewhat difficult to determine the transportation requirements for the decentralized-deployed case. The latest Air Force unit type code (UTC) list describes several different F-15 and F-16 independeOnt (that is, capable of operating by themselves) JEIM UTCs ranging in weight from 25 to 50 short tons. [9] A very conservative assumption that 50 short tons must be moved to the F-16 FOL and 100 short tons to the F-15 FOL means that the airlift requirement for this option is 1.2 C-5 sorties for the aircraft with F100-229 engines during the first 30 days of the MTW. [10] JEIM deployment for the 220 engine requires movement of 250 short tons or 3.8 C-5 equivalents.

The decentralized no-deployment structure requires intertheater transportation between FOLs and JEIM shops. It is estimated that an average of 40 F100-229 engines would be returned during the first 2 weeks of the MTW and 10 engines per week would be returned during sustainment operations. This equates to a lift requirement that would need 1.7 C-5s each way during the first 2 weeks of the war and 6.8 C-5s for the remainder of the war. Fighters with 220 engines require an average of 1.6 C-5 transportation equivalents per week during the MTW. These numbers reflect the gross capacity needed, presumably supplied by an ongoing airlift operation that shares transportation space with other needs.

The transportation requirement for the FSL scenario is the same for the decentralized no-deployment scenario. The decentralized-FSL structure, however, can meet this requirement with intratheater assets or about 10 per week for the 229 engines and about 24 per week for the 220 engines. The complete result of the transportation analysis is shown in Table 1.

TF-34 Engine Analysis

As part of the study, the usefulness of alternatives for repair of the TF-34 were also examined. The T-34 is a nonmodular engine that entered service in the late 1970s. The aircraft it powers, the A-10, has been retained in greater numbers than planned following its performance in Iraqi and Kosovo operations. Because of its smaller thrust and lack of an afterburner, it has a lower removal rate than the F100 engines analyzed.

Current repair for the TF-34 features both centralized and decentralized structures. JEIM for Spangdahlem AB and for Pope AFB, North Carolina, for example, moved to Shaw AFB when A-10s were withdrawn from Shaw, freeing JEIM capabilities. As with the other engines, a comparison was made with the performance of centralized and decentralized alternatives in a scenario featuring a single MTW, using current spare levels and empirical ENMCS and repair times from the Shaw JEIM. [11]

A similar MTW scenario was used for this engine. Simulated JEIM performance showed a slowly declining number of spares available over the course of the conflict. This pattern is primarily due to an interaction between the number of available spares and the relatively long time needed to repair the TF-34. Repair at consolidated locations or at home bases functions best, providing the highest number of spares throughout the conflict.