Keystone B-5

{{Infobox aircraft

|name=B-5

|image=Keystone B-5A front left quarter 060421-F-1234P-017.jpg

|caption=Keystone B-5A

|type=Light bomber

|manufacturer=Keystone Aircraft

|designer=

|first_flight=

|introduction=

|retired=

|status=

|primary_user=United States Army Air Corps

|more_users=

|produced=

|number_built= 3 Y1B-5
27 B-5A

|unit cost=

|developed_from=Keystone B-3

|variants=

}}

The Keystone B-5 is a light bomber made by the Keystone Aircraft company for the United States Army Air Corps in the early 1930s. The B-5A was a Keystone B-3A with Wright Cyclone rather than Pratt & Whitney engines.

Design and development

Three B-3A (LB-10A) were reengined with Wright R-1750-3 radial engines and were redesignated Y1B-5. The Army Air Corps changed the design of the last 27 LB-10As on order, replacing the Pratt & Whitney R-1690 radial engines with the Wright R-1750-3. The Pratt & Whitney-powered aircraft were designated B-3A, and the Wright-powered aircraft became B-5A. They provided the backbone of the U.S. bomber force from then to 1934.

Operational history

B-5A were first line bombers of the United States for the period between 1930 and 1934. Afterwards, they remained in service primarily as observation aircraft until the early 1940s.

Variants

;LB-14

:Designed as LB-10 with 575 hp (429 kW) Pratt & Whitney GR-1860 engines; three ordered, but redesigned with 525 hp (392 kW) Wright R-1750-3 engines and delivered as the Y1B-5.

;Y1B-5

:Three pre-production aircraft redesignated from LB-14 before delivery.

;B-5A

:Wright R-1750-3 version originally ordered as B-3A, 27 built

Operators

;{{flag|United States|1912}}

Specifications (B-5A)

{{Aircraft specs

|prime units?=imp

|ref=

|crew=5

|length ft=48

|length in=10

|length m=14.9

|span ft=74

|span in=8

|span m=22.8

|height ft=15

|height in=9

|height m=4.8

|wing area sqft=1145

|wing area sqm=106.4

|empty weight lb=7705

|empty weight kg=3945

|gross weight lb=12952

|gross weight kg=5875

|eng1 number=2

|eng1 name=Wright R-1750-3

|eng1 type=radial engines

|eng1 hp=525

|eng1 kw=392

|max speed mph=111

|max speed kts=97

|max speed kmh=179

|cruise speed mph=98

|cruise speed kts=86

|cruise speed kmh=160

|range miles=815

|range nmi=707

|range km=1,310

|ceiling ft=14,000

|ceiling m=4,270

|wing loading lb/sqft=273.3

|wing loading kg/m2=52.22

|power/mass=0.0810 hp/lb (133 W/kg)

|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

}}

See also