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The criterion for the GE-90 engine, including all controls and accessories, was to achieve a robust design with Early ETOPs certification. The start requirements of this engine dictated a starter in the 310Kw/1440N-m range that would fit in a 33-cm long by 25-cm wide envelope and weigh less than 24.5 Kg. These requirements made it necessary to develop a new start system for this application. A multi-company Integrated Product Development (IPD) team was formed to identify reliability drivers and develop design improvements. The team achieved the program's objectives and pioneered many new features to meet the goals.

Since introduction into service, the B737-300 starter has been susceptible to clutch damage. At the onset of the problem, a team was formed to identify the causes of clutch damage and shear shaft failures and to define a corrective action. Several in-service airplanes were equipped with recording instrumentation, and data from over 10,000 start cycles was recorded. It was noted that large pneumatic duct pressure fluctuations from a variety of causes played an important role in the reason for the starter reliability problem. After understanding the problem, a design improvement program was launched to replace the current pawl-and-ratchet clutch with an inner-race overrunning sprag clutch that would be capable of withstanding resulting duct pressure fluctuations.