DEVELOPMENT PROGRESS NEW TRANSPORT ENGINES JT9D

The means by which Pratt & Whitney Aircraft is bringing about improvements in its JT9D engine are described. The JT9D engine, having accumulated a year and a half of commercial service, benefits both from a product improvement effort aimed at developing fixes for current operating problems and from development work on advanced JT9D models designed to power future transport aircraft. An extended comparison between the current JT9D-3A engine and the first advanced JT9D (the JT9D-7) illustrates the product improvement process in detail.