As with any radical change to an existing technology, especially a jet engine, a large installed base of expertise together with lots of regulation mean it can be hard for a newcomer to make headway.

因为对于一个已存在技术的根本性的改变，尤其是对飞机引擎来说，大规模基础的专业知识和数量繁多的规章制度使得新来者很难取得进展。