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6 Temmuz 2008 Pazar

F-8 Crusader



The F-8 Crusader (originally F8U) was a single-engine aircraft carrier-based fighter aircraft built by Chance-Vought of Dallas, Texas, USA. It replaced the Vought F-7 Cutlass. The first F-8 prototype was ready for flight in February 1955, and was the last American fighter with guns as the primary weapon. The RF-8 Crusader was a photo-reconnaissance development and operated longer in U.S. service than any of the fighter versions. RF-8s played a crucial role in the Cuban Missile Crisis, providing essential low-level photographs impossible to acquire by other means. Naval Reserve units continued to operate the RF-8 until 1987.

In September 1952, United States Navy announced a requirement for a new fighter. It was to have a top speed of Mach 1.2 at 30,000 ft (9,150 m) with a climb rate of 25,000 ft/min (127 m/s), and a landing speed of no more than 100 mph (160 km/h). Korean War experience had demonstrated that 0.50 in (12.7 mm) machine guns were no longer sufficient and as the result the new fighter was to carry a 20 mm (0.8 in) cannon. In response, the Vought team led by John Russell Clark created the V-383. Unusual for a fighter, the aircraft had a high-mounted wing which allowed for short and light landing gear.


NASA's F-8C digital fly-by-wire testbed.

The most innovative aspect of the design was the variable-incidence wing which pivoted by 7° out of the fuselage on takeoff and landing. This afforded increased lift due to a greater angle of attack without compromising forward visibility because the fuselage stayed level. Simultaneously, the lift was augmented by leading-edge slats drooping by 25° and inboard flaps extending to 30°. The rest of the aircraft took advantage of contemporary aerodynamic innovations with area ruled fuselage, all-moving stabilators, dog-tooth notching at the wing folds for improved yaw stability, and liberal use of titanium in the airframe. Power came from the Pratt & Whitney J57 afterburning turbojet and the armament, as specified by the Navy, consisted of four 20 mm cannon, a retractable tray with 32 unguided Mighty Mouse FFARs, and cheek pylons for two AIM-9 Sidewinder air-to-air missiles. Vought also presented a tactical reconnaissance version of the aircraft called the V-382. The F-8 Crusader would be the last U.S. fighter designed with guns as its primary weapon.

Major competition came from Grumman with the F-11 Tiger, McDonnell with upgraded twin-engine F3H Demon (which would eventually become the F-4 Phantom II), and North American with their F-100 Super Sabre adopted for carrier use and dubbed the Super Fury.

In May 1953, the Vought design was declared a winner and in June, Vought received an order for three XF8U-1 prototypes (after adoption of the unified designation system in September 1962, the F8U became the F-8). The first prototype flew on 25 March 1955 with John Konrad at the controls. The aircraft exceeded the speed of sound during its maiden flight. The development was so trouble-free that the second prototype, along with the first production F8U-1, flew on the same day, 30 September 1955. On 4 April 1956, the F8U-1 performed its first catapult launch from USS Forrestal.

6 Şubat 2008 Çarşamba

Lockheed YF-12



National Museum of USAF Lockheed YF-12

The Lockheed YF-12 was an American prototype interceptor aircraft, which the United States Air Force evaluated as a development of the CIA's highly-secret A-12 OXCART that also spawned the now-famous SR-71 Blackbird.

Design and development

The United States Air Force (USAF) YF-12 program was a development of the Lockheed A-12 OXCART spy plane designed for the CIA and first flown 26 April 1962, the first YF-12A flew on 7 August 1963. The existence of the aircraft was not officially revealed until 29 February 1964. Lockheed was able to interest the Air Force in the project after the United States Air Force had been forced to cancel the XF-108 Rapier, a Mach 3-capable interceptor intended to replace the F-106 Delta Dart in service. It was pointed out that an aircraft based on the A-12 would provide a less costly alternative to the XF-108, since much of the design and development work on the YF-12 had already been done and paid for. In 1960, the USAF agreed to take the 11th through 13th slots on the A-12 production line and have them completed in the YF-12A interceptor configuration.

The main changes involved modifying the aircraft's nose to accommodate the Hughes AN/ASG-18 fire-control radar originally developed for the XF-108, and the addition of a second cockpit for a crewmember to operate the fire control radar. The nose modifications changed the aircraft's aerodynamics enough to require ventral fins to be mounted under the fuselage and engine nacelles to maintain stability. Finally, bays previously used to house the A-12's reconnaissance equipment were converted to carry four Hughes AIM-47A (GAR-9) missiles.

SPECIFICATIONS:

Span: 55 ft. 7 in.
Length: 101 ft.
Height: 18 ft. 6 in.
Weight: 127,000 lbs. loaded
Armament: Three Hughes AIM-47A missiles
Engines: Two Pratt & Whitney J58s of 32,000 lbs. thrust each with afterburner
Crew: Two

PERFORMANCE:

Maximum speed: Mach 3+
Range: 2,000+ miles
Service ceiling: Above 80,000 ft.