XP-58 Chain Lightning

P-58 Chain Lightning
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The sole completed XP-58
Type	Heavy fighter
Manufacturer	Lockheed
Maiden flight	1944-06-06
Status	Cancelled
Number built	1

The Lockheed XP-58 Chain Lightning was an American long-range fighter developed during World War II.

Development

The XP-58 was a Lockheed Aircraft Company 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 April 20, 1940. Initially, two designs were formulated, both using the Continental IV-1440 engines. One would be a single seat aircraft with one 20 mm cannon and four 0.5 in (12.7 mm) machine guns. The second would be a two seat aircraft with the addition of a flexible 0.5 in (12.7 mm) gun at the end of each tail boom.

By July 1940, when use of the Pratt & Whitney XH-2600 was entertained, it was decided that the aircraft would have two seats, and the aircraft was designated XP-58. 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 Wright R-2160 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 0.5 in (12.7 mm) machine guns. As support equipment for the two crewmen was added the estimated weight of the XP-58 grew to 34.242 lb (15.532 kg) by August 1941.

As vacillation continued over the engine and role of the XP-58, the A.A.F. agreed to a Lockheed proposal for a second XP-58 that would incorporate features to obtain a range of 3,000 miles (4,800 km). Then, in September 1942, a decision was made to convert the aircraft for a role as a low altitude tank-killer, which introduced complications as the Beechcraft XA-38 Grizzly was being developed for this role. As a result, the second XP-58 was canceled and the role of the design reverted to that of a high altitude fighter, but one using 75 mm cannon to breakup bomber formations.

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 June 6, 1944, but flight test work on the XP-58 took second place to other higher priority developments. Eventually twenty-five test flights were completed. The XP-58 was then flown to Wright Field for A.A.F. acceptance tests, even though the turbo-superchargers were experiencing torching, cockpit pressurization and armament with its fire-control equipment were also not installed. Although the prototype arrived at Wright Field on October 22 1944 the aircraft was a maintenance headache and no further trials were conducted. The construction of the second prototype was abandoned.

Specifications (XP-58)

General characteristics

• Crew: two, pilot and gunner
• Length: 49 ft 4 in (15.0 m)
• Wingspan: 70 ft (21.3 m)
• Height: 16 ft (4.9 m)
• Wing area: 600 ft² (56 m²)
• Empty weight: 21,624 lb (9,808 kg)
• Loaded weight: lb (kg)
• Max takeoff weight: 39,192 lb (17,777 kg)
• Powerplant: 2× Allison V-3420 24 cylinder liquid-cooled engines, 3,000 hp (2,200 kW) each

Performance

• Maximum speed: 436 mi/h at 25,000 ft (702 km/h)
• Range: statute miles (km)
• Service ceiling: 38,400 ft (11,700 m)
• Rate of climb: 2,660 ft/min (13.5 m/min)
• Wing loading: kg/m² (lb/ft²)
• Power/mass: 0.15 hp/lb (0.12 kW/kg)

Armament

• Four 37 mm cannon and four 0.5 in (12.7 mm) machine guns in two remotely controlled flexible turrets or,
• One 75 mm cannon and two 0.5 in (12.7 mm) machine guns in the nose and two turrets.

References

• William Green (1961). War Planes of the Second World War - Fighters, (Vol 4). London: MacDonald

Related content

Comparable aircraft

• Bristol Beaufighter
• P-61 Black Widow

Designation sequence

• Pre-1948 USAAC/F:
  • XP-55 - XP-56 - XP-57 - XP-58 - P-59 - P-60 - P-61

See also

• List of Lockheed aircraft