Boeing Y1B-20

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 (Y1- indicates a funding source outside normal fiscal year procurement.) 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.

Specifications (as designed)

General characteristics

• Crew: 10
• Length: 109 ft 2 in (33.3 m)
• Wingspan: 157 ft 0 in (47.8 m)
• Height: 23 ft 4 in (7.1 m)
• Wing area: ft² (m²)
• Empty weight: 87,500 lb (39,700 kg)
• Loaded weight: 91,500 lb (41,500 kg)
• Max. takeoff weight: 105,100 lb (47,700 kg)
• Powerplant: 4 × Wright GR-2600-A73, 1,350 hp (1,000 kW) each

Performance

• Maximum speed: 258 mph (224 knots, 415 km/h)
• Cruise speed: 242 mph (210 knots, 389 km/h)
• Range: 4,000 mi (3,500 nm, 6,400 km)
• Power/mass: 0.059 hp/lb (97 W/kg)

Armament

• Guns:
  
  • 3× .30 in (7.62 mm) machine guns
  • 4× .50 in (12.7 mm) machine guns
• Bombs: 17,600 lb (6,620 kg)

See also

Related development

• Boeing XB-15

Aircraft of comparable role, configuration and era

• Douglas XB-19
• Martin XB-16
• B-29 Superfortress

Related lists

• List of bomber aircraft
• List of military aircraft of the United States

External links

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