Boeing Y1B-20
Role Heavy bomber
Manufacturer Boeing
First flight n/a
Status Cancelled
Primary user United States Army Air Forces
Number built 0
Developed from Boeing XB-15

The Boeing Y1B-20 (Boeing 316) was designed as an improvement on the Boeing XB-15.[a] 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]

Specifications (as designed)

General characteristics



See also

Related development

Aircraft of comparable role, configuration, and era

Related lists


  1. ^ Y1- indicates a funding source outside normal fiscal year procurement.
  1. ^ Kohn, Leo. "Boeing XB-15 Super Flying Fortress: U.S. Heavy Bomber". In Ray Merriam (ed.). U. S. Warplanes of World War II. World War II Journal. Vol. 69. Merriam Press. pp. 43–44. ISBN 1-57638-167-6.