of the Big Triangle First. Elsenham, UK: East Anglia Books, 1986. . Freeman, Roger A. The Mighty Eighth War Diary. St. Paul, Minnesota: Motorbooks International, 1990. . Freeman, Roger A. The Mighty Eighth War Manual. St. Paul, Minnesota: Motorbooks International, 1991. . Galland, Adolf. The First and the Last: Germany's Fighter Force in WWII (Fortunes of War). South Miami, Florida: Cerberus Press, 2005. . Levine, Alan J. The Strategic Bombing of Germany, 1940–1945. Westport, Connecticut: Praeger, 1992. . External links YB-40 Gun Ship Completes a Successful Mission USAF Factsheet, Boeing YB-40 Flying Fortress The YB-40 gunship was both more and less than planners expected B-40 Flying Fortress Boeing B-40 Flying Fortress 1940s United States fighter aircraft Four-engined tractor aircraft Low-wing aircraft B-40 Aircraft first flown in 1942 Four-engined piston aircraft