Boeing Y1B-20 explained

The Boeing Y1B-20 (Boeing 316) was designed as an improvement on the Boeing XB-15. It was slightly larger than its predecessor, and was intended to use much more powerful engines. It was presented to the Army in early 1938, and two orders were placed soon after. The order was reversed before construction began.

Despite their cancellation, the XB-15 and Y1B-20 laid the groundwork for the Boeing B-29 Superfortress.^[1]

External links

• Encyclopedia of American Aircraft
• USAF Museum description of Y1B-20

Notes and References

1. Book: Kohn, Leo. Boeing XB-15 Super Flying Fortress: U.S. Heavy Bomber. Ray Merriam. U. S. Warplanes of World War II. Merriam Press. 43–44. 1-57638-167-6. 69. World War II Journal. July 2000 .