Subject: Bomber Series--Keystone LB-10

From: [email-masked]
Date: 13 Jun 94 16:56:10 GMT

>From [email-masked]

The 17th production Keystone LB-6 on the 1929 contract (29-027) was 
completed as the LB-10.  The LB-10 differed from the LB-6 in being 
powered by by a pair of experimental 525 hp Wright R-1750-1 Cyclone 
radial engines, plus it had a single rudder in place of the twin 
rudders which Keystone had standardized on the LB-5A.  

The single-rudder adaptation introduced by the LB-10 impressed the 
USAAC, and 63 examples were orderd under the designation LB-10A.  The 
LB-10A differed from the LB-10 in being powered by a pair of Pratt & 
Whitney R-1690-3 radials.  The LB-10A had a slightly smaller wingspan 
and had a slightly shorter fuselage, but was otherwise similar to the 
LB-10.  However, before the first LB-10A could be delivered, the USAAC 
had dropped the LB designation and was listing all of its bombers 
under the B series.  

Specification of the Keystone LB-10: 

Two 525 hp Wright R-1750-1 Cyclone alr-cooled radial engines.  Maximum 
speed 116 mph at sea level, 113 mph at 5000 feet.  Cruising speed 93 
mph.  Landing speed 58 mph.  Service ceiling 13,440 feet.  Absolute 
ceiling 15,800 feet.  Initial climb rate 660 feet per minute.  An 
altitude of 5000 feet could be attained in 9 minutes.  Range was 350 
miles with 2587 pounds of bombs.  Weight: 6993 pounds empty, 13,285 
pounds gross.  Wingspan 75 feet, length 49 feet 3 inches, height 15 
feet 6 inches, wing area 1148 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
1000 E. Warrenville Road		Naperville, Illinois 60566-7013