Lockheed XP-58 Chain Lightning

Le XP-58 de Lockheed sur Wikipedia de langue anglaise

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The Lockheed XP-58 Chain Lightning was an [Vous devez être inscrit et connecté pour voir ce lien] long-range fighter developed during [Vous devez être inscrit et connecté pour voir ce lien].

Although derived from the successful [Vous devez être inscrit et connecté pour voir ce lien], the XP-58 was plagued by technical problems with its engines that eventually led to the cancellation of the project.

Design and development

The XP-58 was a [Vous devez être inscrit et connecté pour voir ce lien] funded initiative to develop an improved Lightning as a long-range fighter following the release by the U.S. Army Air Corps of the Lightning for sale to Britain on 20 April 1940.

Initially, two designs were formulated, both using the [Vous devez être inscrit et connecté pour voir ce lien] engines.

One would be a single seat aircraft with one 20 mm (.79 in) cannon and four .50 in (12.7 mm) machine guns.

The second would be a two-seat aircraft with the addition of a flexible .50 in (12.7 mm) gun at the end of each tail boom.^{[Vous devez être inscrit et connecté pour voir ce lien]}

In July 1940, it was decided to switch to [Vous devez être inscrit et connecté pour voir ce lien] engines as aircraft would be underpowered with the Continental engines, with the aircraft having two seats and designated XP-58.


^{[Vous devez être inscrit et connecté pour voir ce lien]}However, soon Lockheed was advised the development of the XH-2600 engine was terminated.


After consideration of the engine alternatives, the design was changed to use two [Vous devez être inscrit et connecté pour voir ce lien] Tornado engines, as well as a change of the rear facing armament to two turrets, one upper and the other lower on the fuselage, each turret containing two .50 in (12.7 mm) machine guns.

As support equipment for the two crewmen was added, the estimated weight of the XP-58 grew to 34,232 lb (15,527 kg) by August 1941.[Vous devez être inscrit et connecté pour voir ce lien]

In March 1942 the USAAF placed an order for a second XP-58 that would incorporate increased fuel tanks to obtain a range of 3,000 mi (4,800 km).


The Air Force were uncertain about the role and armament of the aircraft, and in September 1942, a decision was made to convert the aircraft for a role as a low-altitude attack aircraft, armed with a 75 mm (2.95 in) M5 autocannon.


Adequate aircraft were already available for this mission, with the [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] under development.


As a result, the second XP-58 was canceled and the role of the design reverted to that of a high-altitude fighter, using large-bore cannon firing high-explosive shells to break up bomber formations.<sup>[Vous devez être inscrit et connecté pour voir ce lien]

[Vous devez être inscrit et connecté pour voir ce lien][Vous devez être inscrit et connecté pour voir ce lien]</sup>The [Vous devez être inscrit et connecté pour voir ce lien] was originally selected for a quadruple mount in the nose, but the trajectory of the 37mm shells dropped lower than other weaponry, limiting its effective range.


An hydraulically-articulated nose that could be bent up to correct this problem was tried, but was dismissed as too complex.


Then, a 75 mm (2.95 in) M5 autocannon paired with twin .50 in (12.7 mm) machine guns was tried and proved much more successful.

Testing

In February 1943, use of another engine, the Allison V-3420, was necessary due to poor progress with the Tornado engine development. With this change, the second XP-58 was resurrected.

The XP-58 finally flew on 6 June 1944, but flight test work on the XP-58 took second place to other higher priority developments.

Eventually, 25 test flights were completed.


The XP-58 was then flown to Wright Field for USAAF acceptance tests, even though the turbo-superchargers were experiencing torching and a number of systems were not installed including provision for cockpit pressurization and armament with its fire-control equipment.


Although the prototype arrived at Wright Field on 22 October 1944, the aircraft was a maintenance headache and no further trials were conducted.

The construction of the second prototype was abandoned.

Specifications (XP-58)

Data from Lockheed Aircraft since 1913<sup>[Vous devez être inscrit et connecté pour voir ce lien]

[Vous devez être inscrit et connecté pour voir ce lien]</sup>General characteristics

• Crew: two, pilot and gunner
  
• Length: 49 ft 5½ in (15.07 m)
  
• [Vous devez être inscrit et connecté pour voir ce lien]: 70 ft (21.34 m)
  
• Height: 16 ft (4.88 m)
  
• Wing area: 600 ft² (55.7 m²)
  
• [Vous devez être inscrit et connecté pour voir ce lien]: 31,624 lb (14,344 kg)
  
• [Vous devez être inscrit et connecté pour voir ce lien]: 39,192 lb (17,777 kg)
  
• Powerplant: 2× [Vous devez être inscrit et connecté pour voir ce lien] 24 cylinder liquid-cooled engine, 3,000 hp (2,238 kW) each
  

On poura dire deux Allison V-1710 "mated to a common crankcase"

Voici l'unique vestige du XP 58

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Une filiation indéniable avec le P 38

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