The B-25 twin-engine bomber aircraft used during World War Two, commonly called the "B-25 Mitchell" in honor of U.S. Army General William "Billy" Mitchell.
2003 Bradley, James ''Flyboys''. New York: Little, Brown and Company. Ch 7:
Just then a squadron of "Billys" -- twin-engined B-25 Mitchell land-based bombers -- flew overhead ....
(given name) borrowed from English.