Leading up to its famous stable of World War 2 heavy bombers, Boeing undertook a variety of projects to further existing technologies and enhance qualities for long endurance flight of heavy airframes. One such program became the Y1B-20 (Boeing Model 316), an offshoot of the experimental XB-15. The original XB-15 was born of a 1933 United States Army Air Corps (USAAC) initiative seeking a bomber capable of 5,000 mile endurance reaching speeds of 200 miles per hour with a 2,000lb bomb load. The Y1B-20 was essentially an evolved, dimensionally larger version designed around use of more powerful engines - 4 x Wright GR-2600-A73 rated at 1,350 horsepower being the intended type. While presented to the Army (and accepted through two prototype orders), the product was cancelled before manufacture of either airframe had begun. As such, no examples were ever completed by Boeing and the project was lost to aviation history.
The four-engine arrangement and general aerodynamic design of the Y1B-20 was estimated to allow for a maximum speed of 258 miles per hour with a cruising speed of 242 miles per hour. Operational range was listed at 4,000 miles. Comparatively, the YB-15 - which saw considerably more interest and usage by the US Army - exhibited a maximum speed of 200 miles per hour and cruising at 150 miles per hour. Range was 5,130 miles while its service ceiling was 18,900 feet. The famous B-17 (G-model) allowed for a maximum speed of 290 miles per hour, cruising at 180 miles per hour, a range of 2,000 miles and a service ceiling of 35,600 feet.
As a heavy bomber, the Y1B-20 was slated to carry ordnance loads up to 17,600lbs internally. As with other bombers of the period, the aircraft was to be defensed through a network of purposefully placed machine guns numbering seven - 3 x 0.30 caliber and 4 x 0.50 caliber in nature.
At any rate, like the XB-15 before it, the Y1B-20 helped Boeing to lay the foundation for its stable of important bombers serving during World War 2 and beyond.
Production 0 Units
Boeing Company - USA
- Ground Attack
- X-Plane / Developmental
109.25 ft (33.3 m)
156.82 ft (47.8 m)
23.29 ft (7.1 m)
87,524 lb (39,700 kg)
105,160 lb (47,700 kg)
(Showcased weight values pertain to the Boeing Y1B-20 production model)
4 x Wright GR-2600-A73 radial piston engines developing 1,350 horsepower each driving three-bladed propeller units.
258 mph (415 kph; 224 kts)
3,977 miles (6,400 km; 3,456 nm)
(Showcased performance values pertain to the Boeing Y1B-20 production model; Compare this aircraft entry against any other in our database)
3 x 0.50 caliber Browning M2 heavy machine guns.
3 x 0.30 caliber Browning M1919 machine guns.
Up to 17,600lb of internal stores (conventional drop bombs).
(Showcased armament details pertain to the Boeing Y1B-20 production model)
Y1B-20 - Base Series Designation
Model 316 - Boeing Company Model Designation
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.
The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com.
Part of a network of sites that includes GlobalFirepower, a data-driven property used in ranking the top military powers of the world and WDMMA.org, the World Directory of Modern Military Aircraft.