Login
Login

Keystone B-3

{{Short description|Bomber aircraft family by Keystone}}

{{Infobox aircraft

|name=B-3A

|image=Keystone B-3A (SN 30-281).jpg

|caption= Keystone B-3A (S/N 30-281), the first B-3A built.

|type=Bomber

|manufacturer=Keystone Aircraft

|designer=

|first_flight=

|introduction=

|retired=

|status=Retired

|primary_user=United States Army Air Corps

|produced=

|number_built=63 B-3A/B-5

|variants= Keystone B-4, B-5 & B-6

}}

The Keystone B-3A was a bomber aircraft developed for the United States Army Air Corps by Keystone Aircraft in the late 1920s.

Design and development

The B-3 was originally ordered as the LB-10A (a single-tail modification of the Keystone LB-6), but the Army dropped the LB- 'light bomber' designation in 1930.

Although the performance of the B-3A was hardly better than that of the bombers flown at the end of World War I, it had come a long way in terms of flight safety.

Operational history

The B-3A was a member of the last family of biplanes operated by the US Army; it remained in service until 1940. A few years after it was first produced, the introduction of all-metal monoplanes rendered it almost completely obsolete.

Variants

;LB-10

:The last of the 17 LB-6s ordered (S/N 29-27) was converted with a re-designed single fin and rudder and two 525 hp Wright R-1750E engines. Delivered to Wright Field on 7 July 1929, it was wrecked on 12 November 1929.

;LB-10A

:This version used Pratt and Whitney R-1690-3 Hornet engines and was slightly smaller, in both wingspan and length. A total of 63 were ordered (S/N 30-281/343). All were re-designated as the B-3A before any deliveries were made, with the final 27 built as B-5A with Wright engines.

;B-3A

:Ordered as LB-10A, 36 delivered as B-3A (S/N 30-281/316). The first aircraft was delivered in October 1930.

;B-5A

:Ordered as B-3A, re-engined with Wright R-1750-3 Cyclone engines, 27 built (S/N 30-317/343).

Operators

;{{flag|United States|1912}}

;{{flag|Philippines|1936}}

Specifications (B-3A)

{{Aircraft specs

|ref =

|prime units? = imp

|crew = 5

|capacity =

|length m = 14.9

|length ft = 48

|length in = 10

|span m = 22.8

|span ft = 74

|span in = 8

|height m = 4.8

|height ft = 15

|height in = 9

|wing area sqm = 106.4

|wing area sqft = 1145

|aspect ratio =

|airfoil =

|empty weight kg = 3495

|empty weight lb = 7705

|gross weight kg = 5875

|gross weight lb = 12952

|max takeoff weight kg =

|max takeoff weight lb =

|more general =

|eng1 number = 2

|eng1 name = Pratt & Whitney R-1690-3

|eng1 type = radial engines

|eng1 kw = 392

|eng1 hp = 525

|eng1 shp =

|eng1 kn =

|eng1 lbf =

|power original =

|thrust original =

|eng1 kn-ab =

|eng1 lbf-ab =

|more power =

|prop name =

|prop dia m =

|prop dia ft =

|prop dia in =

|rot dia m =

|rot dia ft =

|rot dia in =

|rot area sqm =

|rot area sqft =

|rot number =

|max speed kmh = 183

|max speed mph = 114

|max speed kts = 98

|max speed note =

|max speed mach =

|cruise speed kmh = 158

|cruise speed mph = 98

|cruise speed kts = 85

|cruise speed note =

|stall speed kmh =

|stall speed mph =

|stall speed kts =

|stall speed note =

|never exceed speed kmh =

|never exceed speed mph =

|never exceed speed kts =

|range km = 1400

|range miles = 860

|range nmi = 760

|range note =

|combat range km =

|combat range miles =

|combat range nmi =

|combat range note =

|ferry range km =

|ferry range miles =

|ferry range nmi =

|ferry range note =

|endurance =

|ceiling m = 3870

|ceiling ft = 12700

|ceiling note =

|climb rate ms = 2.7

|climb rate ftmin = 530

|climb rate note =

|sink rate ms =

|sink rate ftmin =

|sink rate note =

|wing loading kg/m2 = 55.42

|wing loading lb/sqft = 11.31

|disk loading kg/m2 =

|disk loading lb/sqft =

|power/mass = 0.0811 hp/lb (133 W/kg)

|thrust/weight =

|more performance =

|guns = 3 × .30 in (7.62 mm) machine guns

|bombs = 2,500 lb (1,100 kg); 4,000 lb (1,800 kg) on short runs

|rockets =

|missiles =

|hardpoints =

|hardpoint capacity =

|hardpoint rockets =

|hardpoint missiles =

|hardpoint bombs =

|hardpoint other =

|avionics = }}

See also

{{aircontent

|related=

|lists=

}}

References

;Notes

{{Reflist}}

;Bibliography

{{Refbegin}}

  • Andrade, John. U.S. Military Aircraft Designations and Serials since 1909. Leicester, UK: Midland Counties Publications, 1979, pp. 43, 135. {{ISBN|0-904597-22-9}}.
  • The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985). London: Orbis Publishing, 1985, p. 2255.
  • Maurer, Maurer. Combat Squadrons of the Air Force, World War II. Maxwell AFB, Alabama: Air Force Historical Studies Office, 1982. {{ISBN|0-89201-097-5}}.

{{Refend}}

External links

{{Commons category|Keystone B-3}}

  • [http://www.joebaugher.com/usaf_bombers/b3.html Encyclopedia of American Aircraft]
  • [http://1000aircraftphotos.com/APS/4234.htm Photograph of B-3 on the ground]
  • [https://airandspace.si.edu/collection-objects/keystone-b-3a-lb-10a-military-usa-army-air-corps-bases-nichols-field-philippines Photograph of B-3 landing] {{Webarchive|url=https://web.archive.org/web/20191007071926/https://airandspace.si.edu/collection-objects/keystone-b-3a-lb-10a-military-usa-army-air-corps-bases-nichols-field-philippines |date=2019-10-07 }}
  • [https://web.archive.org/web/20131029210228/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2408 USAF Museum article on LB-10]
  • [https://web.archive.org/web/20131029211809/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2394 USAF Museum article on B-3]

{{Keystone aircraft}}

{{USAF bomber aircraft}}

{{Authority control}}

B-3

Category:Light bombers

Keystone B-03

Category:Biplanes

Category:Twin piston-engined tractor aircraft