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

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This study evaluated several maintenance policies for F100-220, F100-229, and TF-34 engines. FSLs for wartime support of fighter engines, with removal rates in the range experienced by the F100 engines, seemed to offer the most attractive policy in terms of serviceable engine availability and its effect on fighter capability. However, the development of any consolidated maintenance structure will require considerable planning from a global, strategic perspective.

The reorganization of the Air Force into an expeditionary aerospace force (EAF) requires reexamination of many combat support areas. One such area is engine maintenance. [1] Traditionally, the jet engine intermediate maintenance shop (JEIM) has been located where the aircraft were flown from (for example, at the forward operating location [FOL] during deployments) and was under the overall command of the operational commander, a concept that was compatible with Cold War conflicts since units planned to operate from relatively fixed locations. Recent EAF support studies show that, in some cases, centralized repair can provide better performance and allow quicker deployments by reducing initial transportation requirements. [2]

The Air Force has attempted centralized jet engine intermediate repair for various engines several times, albeit with varying success. It centralized JEIM for the Pratt & Whitney F100-220 engine at the San Antonio Logistics Center under the control of the Air Force Logistics Command (later Air Force Materiel Command). Operating units opposed this experiment, and it was ended within 2 years. Nevertheless, reduced fleet sizes and problems in recent years in retaining skilled personnel has led to JEIM centralization for the F110 engine at Misawa AB, Japan; the B1-B engine at Dyess AFB, Texas, and McConnell AFB, Kansas; and the TF-34 engine at Shaw AFB, South Carolina, and several Air National Guard (ANG) units.

With the advent of the EAF, interest in centralization has been renewed because of difficulties in moving a complete airbase structure to a bare base within a very short period of time. Recent experience showed that centralization is useful in some circumstances. Examples are Operation Noble Anvil (the air operation in Kosovo) when logisticians established centralized engine repair facilities at European bases to support forces deploying to new operating locations (southern Italy) or those with limited or overtaxed facilities (Aviano AB, Italy). The JEIM at RAF Lakenheath, United Kingdom, supported several F-15E deployments to other bases. Centralized JEIM at Spangdahlem AB, Germany, supported ANG A-10s operating in Italy and stood ready to supply additional F100 engine repair as needed.

However, working against centralization is the fact that transporting engines for repair is more difficult than shipping other commodities such as avionics whose support might also be centralized. Also, jet engines are subject to numerous time change technical orders, some requiring attention that a centralized repair structure might not be able to perform immediately for a large fleet. Further, the issue of control over maintenance assets remains a significant, if unarticulated, concern to wing commanders.

RAND evaluated several engine maintenance alternatives in support of expeditionary operations:

* The current decentralized-deployed system, in which part of the JEIM at each base deploys with its unit to an FOL to form a deployed JEIM (DepJEIM).

* Decentralized no-deployment, in which there is no JEIM deployment and repairs are done at the home base, even during contingencies.

* A decentralized forward-support-location (FSL) structure, in which each base has its own JEIM but, during war, some personnel from each deploy to a single FSL to support all units in theater.

* A structure combining FSLs with a continental United States (CONUS) support location (CSL) supporting all units in peacetime with JEIM personnel deploying to a theater FSL during war (CSL-FSL).

* CSL-only, in which JEIM is done at a CSL in both peace and war (CSL).

In evaluating these options, a primary consideration was system performance and the ability to respond to unforeseen events. The major elements involved in system performance include spare engines, personnel, and transportation resources. The major focus, however, is on spare engines as a key measurement because sufficient spares ensure that sorties are being executed and provide a hedge against uncertainty and surprises in operating demands.

Simulating Demand and Need

Although helpful for insight into past problems and in choosing alternatives to evaluate, data from previous centralization efforts cannot be used to evaluate the alternatives. This is true for several reasons. First, data on system performance, particularly during conflict and pre- and post-centralization efforts, are limited. Second, several previous centralization efforts faced unique external constraints that may not apply in general situations. Finally, some of the centralization alternatives have not been tried for particular engine types; that is, for engines with repairs that were never centralized (for example, the F100-229), only partially centralized (for example, the TF-34), or not centralized during conflict (for example, the F100-220).