Military

F101

The General Electric F101, a moderate bypass ratio turbofan engine, was originally developed for the Advanced Manned Strategic Aircraft program, which became the B-1 strategic bomber. Utilizing the same core design as the F101, the F110 and F118 engine derivatives were created by adding new low pressure systems to tailor engine performance to the desired aircraft application.

Rated in the 30,000 pound thrust class, the F101 was the first GE-produced turbofan with an augmentor. Initiated in 1968, the F101 engine was scheduled for preliminary flight rating test (PFRT) in October 1973. The FlOl engine achieved over 20,000 operational test hours in the B-l development program. Although the planned production program was terminated in 1977, four B-1 aircraft were built and flown through a complete operational flight test program.

Virtually all large civil transport engines evolved from military programs, and in many cases, were direct derivatives of engines developed for the military. The CFM56 engine, used in most Boeing 737 aircraft, is based on the core of the F101 engine used in the B-1. A joint company was formed by the General Electric Company, US, and the Societe Nationale d'Etude et de Construction de Moteurs d'Aviation (SNECMA), France, to develop a 'ten-ton' high bypass turbofan engine for commercial and military use. The engine, designated CFM56, was based to a large extent on the core of the F101 engine which powers the B-1 bomber Hardware design and development initiated in 1973 led to the construction of four test engines by 1976.

GE received a contract to develop the F101-102 augmented turbofan, an improved version from the earlier flight test engine for the B-1B. The first engine was delivered in 1983 and B-1B flight testing began in 1984. The U.S. Air Force accepted the first aircraft in 1985 and the last of 469 F101-GE-102 engines was produced in December 1987.

DoD experienced significant problems with P&W TF30-powered F-14s and P&W F100-powered F-15s and F-16s. The high performance (7.6 to 1 thrust to weight ratio) of the F100 engine led to a number of problems in terms of reliability and durability. The F101 engine with a thrust to weight ratio of 7.3 to 1 was developed with a greater emphasis on reliability and long service life at the expense of light weight construction. However, with an expected thrust of 26-29,000 lb., the F101 would still supply a better aircraft thrust to weight ratio than the F100 in spite of its greater weight. Over a two-year period, Congress added $41 million to the Navy budget to begin a TF30 replacement program. When the Navy failed to spend the $41 million, and when problems with the F100 worsened, the money was shifted to the Air Force to develop an engine to compete with the F100. That engine, a derivative of the GE F101 engine for the B-1 bomber, was ultimately designated the F110. The FlOl Derivative Fighter Engine (DFE) program was part of the Department of Defense's (DOD's) comprehensive fighter aircraft engine program designed to correct current engine problems and to meet midterm and long-term engine needs. The objective of the FlOlDFE program was to modify the FlOl engine, designed for the B-l bomber, as an alternative or backup engine for the TF30 (F-14) and FlOO (F-16) engines should their Component Improvement programs (CIPs) fail to resolve the engines' operability and supportability problems.

By 1980 the TF30 and FlOO engines' problems, although different, generally consisted of compressor stalls and stagnations, turbine failures, and lower than desired durability of engine components. Compressor stalls, stagnation, and turbine failures have adversely affected flight safety. Collectively the problems result in reduced operational readiness, increased spare parts costs, and extensive and costly CIPs and retrofits. From initiation of the engines' production in 1971 (TF30) and 1973 (FlOO) to 1979, the services spent about $534 million to correct the problems. Although some improvements have been made, major problems remained.

The FlOl had never flown operationally and had not matured beyond its development as a bomber engine. Modifications to enable usage of the FlOl engine in the fighter aircraft included development of a new fan, low-pressure turbine, afterburner, nozzle, outer casing, and resizing to fit into the F-14 and F-16 airframes. In testimony before the House Armed Services Committee, a Navy official described this effort as extensive, both in terms of redesign and development.

The FlOlDFE was the beneficiary of a $1 billion investment in technology accumulated over the 12 years -- l968 to 1980. This investment included a number of successful engine development programs -- FlOl/B-1 ($621 million), CFM56 using the FlOl core ($109 million), YJlOl/YF-17 ($31 million), and F404/F-18 ($250 million). The FlOlDFE is based on proven and demonstrated technology from the above programs and, in many cases, uses identical components from the FlOl engine.

Beginning in the 1980s, the "Great Engine War" pitted the F100 against the F110. In 1984, the U.S. Air Force selected GE's F110 engine, based on the F101 design, as one of the engines for the F-16C/D fighter aircraft. The F110 also powered F-16s worldwide as well as Japan's single-engine F-2 fighter aircraft and the U.S. Navy's F-14B/D Super Tomcat fighter. The F110 was initially selected for new F-14s and F-16s and also to re-engine older F-14s. Until recently, only P&W's F100 has powered F-15s. However, in 2002, Korea selected GE to power its fleet of F-15s, and in 2005, GE was also selected topower Singapore's F-15s. A derivative of the F110, the F118, powered the B-2 bomber.

Advanced Planning System (APS) is a commercial off-the-shelf technology used for supply chain planning and decision support functions. The F101 APS Pathfinder team successfully evaluated APS capabilities and limitations in the depot environment by successfully implementing strategies and solutions on the F101 engine for the B-1B "Lancer" bomber aircraft. The APS Pathfinder team provided an integrated, near real-time, responsive approach to planning and assessment of feasible execution plans through an enterprise-wide view of all related Air Force logistical organizations.

The APS Pathfinder effort demonstrated the capability to provide an automated, alerts-based capability to identify, examine and resolve potential supply chain issues by exception (demand variability, parts availability, physical capacity, financial restrictions) before impacting daily execution. The Pathfinder also established a mechanism for sharing information and supporting collaborative planning capabilities across the extended supply chain (for example, Defense Logistics Agency (DLA) and Original Equipment Manufacturer's (OEM's)). This fully integrated functionality enabled the rapid and repetitive modeling and collaboration of supply chain related functions inside and outside an enterprise e.g., forecasting, inventory & distribution planning, rough-cut capacity planning, etc. APS technology, as demonstrated by the Pathfinder, provided increased speed and functionality through the integration of industry developed best business practices.




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