Editing Keystone B-6

{{short description|Biplane bomber of the United States Army Air Corps}}
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{{Infobox aircraft
 |name=B-6
 |image=Keystone B-6A.jpg
 |caption= Keystone B-6A of the 1st Bomb Squadron, 9th Bomb Group, Mitchel Field, N.Y.
 |type=[[Light bomber]]
 |manufacturer=[[Keystone Aircraft]]
 |designer=
 |first_flight=
 |introduction=
 |retired=
 |status=
 |primary_user=[[United States Army Air Corps]]
 |more_users=
 |produced=
 |number_built= 5 Y1B-6 + 39 B-6A
 |unit cost=
 |developed_from=[[Keystone B-3]]
 |variants=
}}

The '''Keystone B-6''' was a [[biplane]] [[bomber aircraft|bomber]] developed by the [[Keystone Aircraft]] company for the [[United States Army Air Corps]].

==Design and development==
In 1931, the [[United States Army Air Corps]] received five working models ('''Y1B-6'''s) of the '''B-6''' [[bomber aircraft|bomber]]. The ''Y1B-'' designation, as opposed to a ''YB-'' designation, indicates funding outside normal fiscal year procurement. Two of these were redesignations of LB-13s; three were re-engined [[Keystone B-3|B-3A]]s. The Air Corps placed an order for 39 production models on 28 April 1931, with deliveries between August 1931 and January 1932.<ref name="Baugher">Baugher, Joe. [http://www.joebaugher.com/usaf_bombers/b6.html "Keystone B-6."] ''American Military Aircraft,'' 11 July 1999. Retrieved: 29 July 2011.</ref>

At the same time, an order was placed for 25 B-4As, the same aircraft but mounting Pratt & Whitney engines instead of Wright Cyclones. Despite their lower sequence number, the B-4As would be delivered last. These were the last canvas-and-wood biplane bombers ordered by the Air Corps.

The performance of the B-6A varied little from the [[Martin NBS-1]] ordered in 1921. Its successor, the monoplane bomber, had a hard time getting accepted. The [[Douglas Y1B-7]] and [[Fokker XB-8]] were originally designed as high-speed reconnaissance aircraft.<ref name="Baugher"/>

==Operational history==
[[File:Keystone B-6 twin-engine airmail plane in snow storm, 1920.jpg|thumb|Keystone B-6 airmail plane in snowstorm, 1934]]
The B-6A together with B-5A were front 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.

B-6 aircraft were used, along with many other Army Air Corps planes, as [[mail plane]]s in what became the [[Air Mail scandal]] of 1934.

On December 27, 1935, six B-6 bombers of the 23rd Bomb Squadron based in Hawaii dropped bombs to divert lava flow from the volcano [[Mauna Loa]] away from the port of [[Hilo]].

With the residents of [[Virginia]]′s [[Tangier Island]] and [[Maryland]]′s [[Smith Island, Maryland|Smith Island]] facing starvation after a severe winter storm and with ships unable to reach the islands due to heavy ice in the [[Chesapeake Bay]], an Army Air Corps [[49th Bomb Squadron]] B-6A made a one-hour, 54-mile (87-km)  flight from [[Langley Field]], [[Virginia]], to Tangier Island on 9 February 1936 to drop {{convert|1,000|lb|kg}} of supplies in {{convert|50|lb|kg|adj=on}} parcels to the islanders, flying at an altitude of not more than {{convert|10|ft|m|abbr=off|sp=us}}. On 10 February, the squadron's B-6As made four similar fights to Tangier Island and one to Smith Island. The flights followed a supply flight to Tangier Island by the [[Goodyear Blimp]] ''Enterprise'' on 2 February 1936. After the success of the B-6A flights, the 49th Bomb Squadron flew additional flights to drop supplies to the islands using 13 [[Martin B-10|Martin B-10B]] bombers.<ref>[https://books.google.com/books?id=OsIBdVV_YOAC&dq=Goodyear+blimp+%22tangier+island%22+1936&pg=PA43 Bentley, Stewart W., Jr., PhD., "The Touch of Greatness: Colonel William C. Bentley, Jr., USAAC/USAF; Aviation Pioneer''], Bloomington, Indiana: AuthorHouse, 2010, {{ISBN|978-1-4490-2386-7}}, pp. 41–42.</ref><ref>Anonymous, "Bombing Planes to Bring Food to Ice Victims," ''Chicago Tribune'', February 2, 1936.</ref>

==Variants==
;LB-13
:Seven aircraft ordered but delivered as the [[Keystone B-4|Y1B-4]] and Y1B-6 with different engine installations.
;Y1B-6
:Two pre-production aircraft and three converted [[Keystone B-3|B-3A]]s, as the LB-10 but with two {{convert|575|hp|kW|abbr=on}} [[Wright R-1820-1]] engines.
;B-6A
:Production version of the Y1B-6, 39 built.

==Operators==
;{{flag|United States|1912}}
*[[United States Army Air Corps]]

==Specifications (B-6A)==
{{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=8057 
|empty weight kg=3665 
|gross weight lb=13350 
|gross weight kg=6056 
|eng1 number=2
|eng1 name=[[Wright R-1820]]-1
|eng1 type=[[radial engine]]s
|eng1 hp=575 
|eng1 kw=429 
|max speed mph=120 
|max speed kts=100
|max speed kmh=190
|cruise speed mph=103 
|cruise speed kts=89
|cruise speed kmh=166
|range miles=825 
|range nmi=717
|range km=1330
|ceiling ft=14100 
|ceiling m=6400 
|wing loading lb/sqft=11.66 
|wing loading kg/m2=56.92 
|power/mass=0.0861 hp/lb (142 W/kg)
|guns=3 × .30 in (7.62 mm) [[Browning Arms Company|Browning]] [[machine gun]]s
|bombs=2,500 lb (1,100 kg); 4,000 lb (1,800 kg) on short runs
}}

==See also==
{{Aircontent
|related=
* [[Keystone B-3]]
* [[Keystone B-4]]
* [[Keystone B-5]]
|similar aircraft=
|lists=
* [[List of bomber aircraft]]
* [[List of military aircraft of the United States]]
}}

==References==
;Notes
{{reflist}}
;Bibliography
{{refbegin}}
* Wagner, Ray. ''American Combat Planes''. New York: Doubleday, 1982. {{ISBN|0-930083-17-2}}.
{{refend}}

==External links==
{{commons category|Keystone B-6}}
*[https://web.archive.org/web/20040804114429/http://www.wpafb.af.mil/museum/research/bombers/b1-49.htm USAF Museum article on B-6]
*[https://web.archive.org/web/20040813193626/http://www.wpafb.af.mil/museum/research/bombers/b1-33.htm USAF Museum article on LB-13]

{{Keystone aircraft}}
{{USAF bomber aircraft}}

[[Category:1930s United States bomber aircraft|Keystone B-06]]
[[Category:Keystone aircraft|B-6]]
[[Category:Biplanes]]
[[Category:Twin piston-engined tractor aircraft]]