The Future of the Allison 250 Engine

The Allison Model 250 small aircraft gas turbine engine is briefly described and the development and field experience highlights are discussed. Recent development effort is outlined on engine response time, sand and dust tolerance, cost reduction, performance growth, regeneration, and augmentation. Variations of the free-turbine engine for a wider variety of applications have been studied. Performance of the 250 engine in fixed-wing commercial aircraft is compared with that of existing piston engines.