Keystone B-6

In 1931, the United States Army Air Corps received five working models (Y1B-6s) of the B-6 bomber. (The Y1B- designation, as opposed to a YB- designation, indicates funding outside normal fiscal year procurement). Two of these were diverted from an order of LB-13s; three were modified B-3As. The performance of the Y1B-6s was very similar to that of the Keystone B-4s, due to an engine of equivalent power.

The production model, called the B-6A, was the last biplane bomber purchased by the Army. The performance of the B-6A varied little from the Martin NBS-1 ordered in 1921. Its successor, the monoplane bomber, had a hard time getting accepted. The Douglas Y1B-7 and Fokker XB-8 were originally designed as high-speed reconnaissance planes.

Specifications (B-6A)

General characteristics

• Crew: 5
• Length: 48 ft 10 in (14.9 m)
• Wingspan: 74 ft 8 in (22.8 m)
• Height: 15 ft 9 in (4.8 m)
• Wing area: 1,145 ft² (106.4 m²)
• Empty weight: 8,057 lb (3,665 kg)
• Loaded weight: 13,350 lb (6,056 kg)
• Max takeoff weight: lb (kg)
• Powerplant: 2× Wright R-1820-1 radial engines, 575 hp (429 kW) each

Performance

• Maximum speed: 120 mph (100 kt, 190 km/h)
• Cruise speed: 103 mph (89 kt, 166 km/h)
• Range: 825 mi (717 kt, 1,330 km)
• Service ceiling: 14,100 ft (6,400 m)
• Wing loading: 11.66 lb/ft² (56.92 kg/m²)
• Power/mass: 0.0861 hp/lb (142 W/kg)

Armament

• Guns: 3× .30 in (7.62 mm) Browning machine guns
• Bombs: 2,500 lb (1,100 kg); 4,000 lb (1,800 kg) on short runs

External links

• USAF Museum article on B-6
• USAF Museum article on LB-13

Related content

Related development

• Keystone B-3
• Keystone B-4
• Keystone B-5

Designation sequence

• LB-series: LB-10 - LB-11 - XLB-12 - LB-13 - LB-14
• B-series: B-3 - B-4 - B-5 - B-6 - Y1B-7 - XB-8 - Y1B-9

Related lists

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