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Keystone XLB-3

Prototype Light Bomber Biplane

Keystone XLB-3

Prototype Light Bomber Biplane

OVERVIEW
SPECIFICATIONS
ARMAMENT
VARIANTS
HISTORY
MEDIA
OVERVIEW



The Keystone XLB-3 was a twin-engine prototype form of the earlier Huff-Daland LB-1 model of 1923.
National Flag Graphic
ORIGIN: United States
YEAR: 1927
MANUFACTURER(S): Keystone Aircraft Corporation . Huff-Daland Aero Corporation - USA
PRODUCTION: 1
OPERATORS: United States
SPECIFICATIONS



Unless otherwise noted the presented statistics below pertain to the Keystone XLB-3 model. Common measurements, and their respective conversions, are shown when possible.
CREW: 5
LENGTH: 45.01 feet (13.72 meters)
WIDTH: 66.99 feet (20.42 meters)
HEIGHT: 16.83 feet (5.13 meters)
WEIGHT (EMPTY): 6,074 pounds (2,755 kilograms)
WEIGHT (MTOW): 11,718 pounds (5,315 kilograms)
ENGINE: 2 x Pratt & Whitney R-1340 engines developing 410 horsepower each.
SPEED (MAX): 116 miles-per-hour (186 kilometers-per-hour; 100 knots)
RANGE: 541 miles (870 kilometers; 470 nautical miles)
CEILING: 11,155 feet (3,400 meters; 2.11 miles)
RATE-OF-CLIMB: 550 feet-per-minute (168 meters-per-minute)




ARMAMENT



STANDARD:
2 x .303 Lewis machine guns in nose on trainable mounting
2 x .303 Lewis machine guns in dorsal cockpit position on trainable mounting.
1 x .303 Lewis machine gun in ventral position on trainable mounting.

OPTIONAL:
Up to 2,205 lb of conventional drop bombs.
VARIANTS



Series Model Variants
• XLB-3 - Base Series Designation; original designation when fitted with 2 x Allison VG-1410 air-cooled inverted V12 engines.
• XLB-3A - Re-engined with 2 x Pratt & Whitney R-1340 radial piston engines.


HISTORY



Detailing the development and operational history of the Keystone XLB-3 Prototype Light Bomber Biplane.  Entry last updated on 5/26/2016. Authored by Staff Writer. Content ©www.MilitaryFactory.com.
As promising as the performance jump from the Martin MB-2 to the Huff-Daland LB-1 series was, Army authorities were not convinced of the merits of a single-engine bomber form. Instead, they elected to pursue a twin-engine variant of the design from Huff-Daland as the "XLB-3". With a twin-engine layout, the crew nacelle was now cleared of complex operating systems which allowed engineers to introduce additional storage and crew operating space - adding a whole new crewmember to the original staff of four. The biplane wing arrangement was retained and each engine drove a two-bladed propeller. All other functions of the aircraft were largely carried over from the preceding design.

The original XLB-3 was outfitted with 2 x Allison VG-1410 (a variant of the "Liberty 12") air-cooled inverted V12 engines of 400 horsepower (each) and it was this prototype form that was handed to the United States Army Air Corps for formal testing in 1927. The crew included two pilots, a bombardier, and two dedicated machine gunners. The defensive gun network included five trainable .303 Lewis machine guns while the offensive bombload carried reached 2,205 lb.

However, performance of the original prototype was less than that of the preceding single-engine LB-1 design which forced a revision of the XLB-3 to become the XLB-3A. This mark was modified through the installation of a pair of Pratt & Whitney R-1340 radial piston engines of 410 horsepower. Beyond that, the design stayed largely faithful to the original offering.

Despite the engine change, the required performance was still lacking and USAAC interest waned as it moved on the related LB-5 instead. The LB-5 found a bit more success in that it was procured in 36 examples from Keystone. Keystone Aircraft Corporation was formed from the purchase of Huff-Daland by Hayden, Stone & Company. Keystone then fell under the Curtiss-Wright brand label from 1929 onwards until its services were terminated in 1932.

Only a single XLB-3 aircraft was ever completed.




MEDIA









Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

Image of collection of graph types

Relative Maximum Speed Rating
Hi: 120mph
Lo: 60mph
    This entry's maximum listed speed (116mph).

    Graph average of 90 miles-per-hour.
City-to-City Ranges
NYC
 
  LDN
LDN
 
  PAR
PAR
 
  BER
BER
 
  MSK
MSK
 
  TKY
TKY
 
  SYD
SYD
 
  LAX
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  NYC
Graph showcases the Keystone XLB-3's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
1
1

  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.


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Supported Roles
A2A
Interception
UAV
Ground Attack
CAS
Training
ASW
Anti-Ship
AEW
MEDEVAC
EW
Maritime/Navy
SAR
Aerial Tanker
Utility/Transport
VIP
Passenger
Business
Recon
SPECOPS
X-Plane/Development
A2A=Air-to-Air; UAV=Unmanned; CAS=Close Support; ASW=Anti-Submarine; AEW=Airborne Early Warning; MEDEVAC=Medical Evac; EW=Electronic Warfare; SAR=Search-Rescue
Supported Arsenal
Graphical image of an aircraft medium machine gun
Graphical image of an aircraft conventional drop bomb munition
Commitments / Honors
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