Keystone XLB-3
{{short description|Prototype Biplane Bomber}}
{{More footnotes|date=April 2017}}
| {{Infobox aircraft begin
|name= XLB-3 |image= File:Keystone XLB-3A.jpg |image_border= yes |caption= XLB-3A }}{{Infobox aircraft type |type= Light bomber |national origin= United States |manufacturer= Keystone Aircraft |designer= |first flight= ca. December 1927 |introduced= |retired= |status= |primary user= United States Army Air Corps |number built= 1 |developed from= |variants with their own articles= }} |
The Keystone XLB-3 (originally built under the Huff-Daland name) was a prototype bomber biplane developed in the United States in the late 1920s. It was a twin-engine development of the single-engine LB-1, brought about by a change in policy by the United States Army Air Corps (USAAC).
Design and development
The shift from a nose-mounted engine to engines mounted in nacelles on the lower wing created an opportunity to provide stations for two extra crewmembers: a bombardier and a nose-gunner, bringing the total to five. The LB-1's single tailfin and rudder was augmented by an extra rudder either side of it.
Operational history
A single prototype was constructed, and delivered to the USAAC for evaluation at the end of 1927. Evaluation, however, showed that performance was actually inferior to that of the single-engine LB-1. The decision was taken to change the XLB-3's air-cooled inverted Liberty engines for air-cooled radials, at which point it was redesignated XLB-3A. With performance still unsatisfactory, development was abandoned in favor of a parallel design, the LB-5.
Variants
- XLB-3 – original version with Allison VG-1410 air-cooled inverted V-12 engines (1 built)
- XLB-3A – version with Pratt & Whitney R-1340 radial engines (1 converted from XLB-3)
Specifications (XLB-3A)
{{Aircraft specs
|ref=Jane's Encyclopedia of AviationTaylor 1989, p. 559.
|prime units? = imp
|crew=Five – pilot, copilot, bombardier, two gunners
|length m=13.72
|length ft=45
|length in=0
|span m=20.42
|span ft=67
|span in=0
|height m=5.13
|height ft=16
|height in=10
|wing area sqm=1,038
|wing area sqft=105.8
|empty weight kg=2,756
|empty weight lb=6,065
|gross weight kg=5,310
|gross weight lb=11,682
|eng1 number=2
|eng1 name=Pratt & Whitney R-1340
|eng1 kw=305
|eng1 hp=410
|max speed kmh=186
|max speed mph=116
|range km=870
|range miles=544
|ceiling m=3,400
|ceiling ft=11,210
|climb rate ms=2.8
|climb rate ftmin=550
|armament = *2 × trainable .303 in (7.7 mm) Lewis guns in open position in nose
- 2 × trainable .303 in (7.7 mm) Lewis guns in open dorsal position
- 1 × trainable .303 in (7.7 mm) Lewis gun in ventral hatch
- 2,205 lb (1,000 kg) of bombs
}}
{{aircontent
|see also=
|related=
|similar aircraft=
|lists=
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References
=Notes=
{{reflist}}
=Bibliography=
{{refbegin}}
- Taylor, Michael J. H. Jane's Encyclopedia of Aviation. London: Studio Editions, 1989.
- World Aircraft Information Files. London: Bright Star Publishing, File 899, Sheet 09.
{{refend}}
External links
{{commons category|Keystone XLB-3}}
- [https://web.archive.org/web/20131004214241/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2427 National Museum of the USAF XLB-3 fact sheet]
- [https://web.archive.org/web/20131004214139/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2428 National Museum of the USAF XLB-3A fact sheet]
- [https://web.archive.org/web/20090102111503/http://home.att.net/~jbaugher2/lb3.html American Bombing Aircraft]
{{Keystone aircraft}}
{{USAF bomber aircraft}}