Subject: Bomber Series--Keystone LB-13

From: [email-masked]
Date: 13 Jun 94 16:56:15 GMT

>From [email-masked]

In 1930, seven Keystone bombers were ordered under the designation 
LB-13.  They were to be equipped with single vertical tails and were 
to be powered by a pair of 525 hp Pratt & Whitney GR-1690 radials.  
Serials were 30-344/353.  In 1930, the USAAC abandoned its separate 
designation categories for light (LB) and heavy (HB) bombers, and 
classified them both under the B category.  Of seven LB-13s ordered, 
five were completed as Y1B-4s with 575 hp R-1860-7 engines (30-344/348 
and the other two as Y1B-6 with 575 hp R-1820-1 engines (30-349/350).  
Three more Y1B-6s were converted from B-3As (30-351/353) 

Specification of the Keystone Y1B-4: 

Two 575 hp Pratt & Whitney R-1860-7 alr-cooled radial engines.  
Maximum speed 121 mph at sea level Weight: 13,011 pounds gross.  
Wingspan 74 feet 9 inches, length 48 feet 10 inches, height 15 feet 9 
inches, wing area 1145 square feet.  Two Lewis machine guns in an open 
gunner's position in the nose, two Lewis machine guns in an open 
dorsal gunner's position, one Lewis gun firing downward through an 
opening in the lower fuselage.  

Specification of the Keystone Y1B-6: 

Two 575 hp Wright R-1820-1 alr-cooled radial engines.  Maximum speed 
120 mph at sea level Weight: 13,300 pounds gross.  Wingspan 74 feet 9 
inches, length 48 feet 10 inches, height 15 feet 9 inches, wing area 
1145 square feet.  Two Lewis machine guns in an open gunner's position 
in the nose, two Lewis machine guns in an open dorsal gunner's 
position, one Lewis gun firing downward through an opening in the 
lower fuselage.  

Sources:

  United States Military Aircraft Since 1909, Gordon Swanborough and
  Peter M. Bowers, Smithsonian, 1989.

  American Combat Planes, Ray Wagner, Third Edition, Doubleday, 1982.

  American Warplanes, Bill Gunston

  Jane's Encyclopedia of Aviation

  U.S. Army Aircraft, 1908-1946, James C. Fahey

Joe Baugher		AT&T Bell Laboratories   	
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