General Atomics Aeronautical Systems has said several times that it is testing a 205-horsepower Lycoming DEL-120 diesel engine on one of its military drones, the Improved Gray Eagle. Lycoming has said in the past that while it has shown interest in development of diesel engines, the time isn’t right. That hasn’t changed. AvWeb’s Paul Bertorelli says Lycoming may just be republishing the DieselJet FIAT 170-horsepower engine intended for cars as a 205-horsepower drone engine. The need for a new engine, he says, was driven by the sale of Thielert, the previous engine provider for the Gray Eagle, to China. The U.S. Army doesn’t want to depend on China for its military engines. While Lycoming’s (Fiat’s?) drone engine gives Lycoming additional experience, it may continue to wait until diesel engines for manned aircraft look like a good business decision. This all came up a few days ago after Andre duCros published an item in his DieselAir newsletter.