View source for Lockheed XB-30

{{short description|American bomber project}}
{{Infobox aircraft
 | name = Lockheed XB-30
 | image = Lockheed XB-30.jpg
 | caption = Scale model of the Lockheed XB-30 bomber concept.
 | type = Heavy bomber
 | manufacturer = [[Lockheed Corporation]]
 | designer = 
 | first_flight = n/a
 | status = Design only
 | primary_user = [[United States Army Air Forces]]
 | number_built = 0
 | developed_from = [[Lockheed L-049 Constellation|L-049 Constellation]]
 | unit cost = 
}}
The '''Lockheed XB-30''' (company model '''L-249''')<ref>Stringfellow and Bowers 1992, p. 31.</ref> was the design submitted by [[Lockheed Corporation|Lockheed]] after the request by the [[United States Army Air Forces]] for a very heavy bomber, the same request that led to the [[Boeing B-29 Superfortress]], the [[Douglas XB-31]] and [[Consolidated B-32 Dominator]].

==Design and development==
Around 1938, General [[Henry H. Arnold|Henry H. "Hap" Arnold]], the head of the [[United States Army Air Corps]], was growing alarmed at the possibility of war in Europe and in the Pacific. Hoping to be prepared for the long-term requirements of the Air Corps, Arnold created a special committee chaired by Brigadier General [[Walter G. Kilner]]; one of its members was [[Charles Lindbergh]]. After a tour of ''[[Luftwaffe]]'' bases, Lindbergh became convinced that [[Nazi Germany]] was far ahead of other European nations.

In a 1939 report, the committee made a number of recommendations, including development of new long-range heavy bombers. When war broke out in Europe, Arnold requested design studies from several companies on a Very Long-Range bomber capable of traveling {{convert|5000|miles|km}}. Approval was granted on 2 December 1939.

Based on the design of the [[Lockheed L-049 Constellation|Lockheed L-049]] (subsequently adopted by the [[United States Army Air Forces]] as the [[Lockheed C-69 Constellation|C-69]]), the L-249 never progressed past the design stage, mainly because [[Boeing]] had a head start with its [[Boeing B-29 Superfortress]] {{citation needed|date=January 2024}}, using the same [[Wright R-3350 Duplex-Cyclone]] radials as the XB-30 was intended to use. Only a scale model was built. Retaining the wings and tail surfaces of the Model 49, the Model 249-58-01 was to have had a new fuselage with up to six gun turrets (one in the nose, two above and two below the fuselage, and one in the tail) housing ten .50-caliber guns—twinned up in each turret for the nose, dorsal, and ventral emplacements; and one 20-mm cannon for the tail defensive position. Ventral bomb bays were to accommodate eight {{convert|2000|lb|kg|abbr=on}} bombs.

==Specifications (as proposed)==
{{Aircraft specs
|prime units?=imp
| ref=
| crew=12
| length ft=104
| length in=8
| length m=31.91 
| span ft=123
| span in=0
| span m=37.50 
| height ft=23
| height in=9
| height m=7.25 
| wing area sqft=1646 
| wing area sqm=153 
| empty weight lb=51616 
| empty weight kg=23462 
| gross weight lb=85844 
| gross weight kg=39020 
| max takeoff weight lb=93808 
| max takeoff weight kg=42640 

| eng1 number=4
| eng1 type=[[radial engine]]s
| eng1 name=[[Wright R-3350 Duplex-Cyclone|Wright R-3350]]-13
| eng1 hp=2200 
| eng1 kw=1600 

| max speed mph=382 
| max speed kmh=615 
| range miles=5,333 
| range km=8,045 
| ceiling ft=17832 
| ceiling m=5,440 
| wing loading lb/sqft=52 
| wing loading kg/m2=255 
|power/mass=0.10 hp/lb (170 W/kg)

| guns=<br />
** 8× .50 in (12.7 mm) [[machine gun]]s in four fuselage turrets
** 2× .50 in (12.7 mm) machine guns ''and''
** 1× [[20 mm caliber|20 mm]] [[autocannon|cannon]] in remotely aimed tail turret
| bombs=16,000 lb
}}

==See also==
{{Aircontent

| related=
* [[Lockheed Constellation]]

| similar aircraft=
* [[Boeing B-29 Superfortress]]
* [[Consolidated B-32 Dominator]]
* [[Douglas XB-31]]
* [[Heinkel He 277]]
* [[Messerschmitt Me 264]]

| lists=
* [[List of Lockheed aircraft]]
}}

==References==
;Notes
{{reflist}}
;Bibliography
{{refbegin}}
* Stringfellow, Curtis K., and Peter M. Bowers. ''Lockheed Constellation''. St. Paul, Minnesota: Motorbooks, 1992.
{{refend}}

==External links==
* [https://web.archive.org/web/20110716073618/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2578 USAF Museum&nbsp;— XB-30 Factsheet]

{{Lockheed Constellation family}}
{{Lockheed Martin aircraft}}
{{USAF bomber aircraft}}

[[Category:Lockheed aircraft|B-030]]
[[Category:Four-engined tractor aircraft]]
[[Category:Low-wing aircraft]]
[[Category:Cancelled military aircraft projects of the United States]]
[[Category:Lockheed Constellation|XB-30]]
[[Category:Four-engined piston aircraft]]
[[Category:Triple-tail aircraft]]
[[Category:Aircraft with retractable tricycle landing gear]]