| XF-88 Voodoo | |
|---|---|
 | |
| General information | |
| Type | Escort fighter |
| Manufacturer | McDonnell |
| Status | Cancelled |
| Primary user | United States Air Force |
| Number built | 2 |
| History | |
| First flight | 20 October 1948 |
| Developed into | F-101 Voodoo |
TheMcDonnell XF-88 Voodoo was a long-range,twinjetfighter aircraft designed for theUnited States Air Force. Although it never entered production, its design was adapted for the subsequent supersonicF-101 Voodoo.
The XF-88 originated from a 1946United States Army Air Forces requirement for a long-range "penetration fighter" to escortbombers to their targets. It was to be essentially a jet-powered replacement for the wartimeNorth American P-51 Mustang that had escortedBoeing B-17 Flying Fortress bombers over Germany. It was to have a combat radius of 900 mi (1,450 km) and high performance. McDonnell began work on the aircraft, dubbed Model 36, on 1 April 1946. On 20 June the company was given a contract for two prototypes designated XP-88.[1]Dave Lewis was Chief of Aerodynamics on this project.[2]
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The initial design was intended to have straight wings and aV-shaped tail, butwind tunnel tests indicated aerodynamic problems that led to a conventional tailplane being substituted and the wings being swept.[1][3] The USAAF confirmed the order for the two prototypes on 14 February 1947,[4] while a change in designation schemes led to the unflown prototypes being re-designated XF-88 on 1 July 1948, with the type gaining the nickname "Voodoo".[1]
The Voodoo had a low/mid-mounted wing,swept to 35°. The two engines, specified asWestinghouse J34turbojets were in the lower fuselage, fed by air intakes in the wing roots and jetpipes beneath the rear fuselage. This made room in the long fuselage for the fuel tanks required for the required long range. The Voodoo's short nose had no radar, being intended to house an armament of six 20 mm (.79 in)M39 cannon, while the fighter's single pilot sat in a pressurized cockpit and was provided with an ejection seat.[5][6]
The first XF-88 made its maiden flight fromMuroc Field on 20 October 1948, piloted by McDonnell Chief Test PilotRobert Edholm.[7][1] It was unarmed and powered by non-afterburning J34-13 engines that gave 3,000 lbf (13.37 kN) thrust.[1] While testing demonstrated adequate handling and the required endurance, the XF-88 proved to be underpowered. This resulted in inadequate performance, with its maximum speed of 641 mph being less than theF-86A then in production.[4] In order to improve performance, it was decided to fit the second prototype's engines with McDonnell-designedafterburners.[8] Thus modified, the engines became J34-22s, giving 3,600 lbf (16.05 kN) thrust.[4] The second prototype, XF-88A, made its maiden flight on 26 April 1949, with the first prototype later modified to the same standard.[8]
The afterburners improved the Voodoo's performance, with the XF-88A reaching 700 mph (1,126 km/h) but at the expense of decreased range owing to increased fuel consumption.[9] Despite this, the XF-88 was chosen against theLockheed XF-90 andNorth American YF-93 for the USAF's Penetration Fighter requirement, with planned production versions to use more powerfulWestinghouse J46 engines.[8] (A 1948 order for 118 F-93s had been cancelled in 1949.[10]) Changes in Air Force priorities, together with a shortage of money, led the penetration fighter to be cancelled in August 1950.[11]
The first prototype was modified to XF-88B standard as a propeller-research vehicle. The model propeller[12] was driven by a nose-mountedAllison T38turboprop which was used to assist in the climb as well as to reach the test conditions. The aircraft was used to test three propellers through1956,[8] to speeds slightly exceedingMach 1.0,[13] the first propeller-equipped aircraft to do so.[8] The propeller was tested in level flight to about M 0.9 with the help of the turbojet afterburners, and to just over M 1.0 in a dive.[12]
McDonnell also proposed a naval version of the XF-88, a two-seat operational trainer, and areconnaissance variant but none were built.[8] Both prototypes were scrapped by1958.[8]
Experience of theKorean War led the USAF to reconsider its plans for penetration fighters and led to a new specification for a long-range fighter, General Operational Requirement (GOR) 101 being issued in February 1951. A considerably enlarged version of the design was chosen to meet this requirement later that year, the revised design becoming theF-101 Voodoo,[3][14] the first production version of which flew on 29 September 1954.[15]
Data from McDonnell Douglas aircraft since 1920 : Volume II,[17] Fighters of the United States Air Force[18]
General characteristics
Performance
Armament
Related development
Aircraft of comparable role, configuration, and era
