Curtiss-Wright XP-55 Ascender
XP-55 Ascender | |
---|---|
![]() Curtiss XP-55 Ascender in flight. | |
General information | |
Type | Fighter |
National origin | United States |
Manufacturer | Curtiss-Wright Corporation |
Status | Canceled at flight-test stage |
Number built | 3 |
History | |
First flight | 19 July 1943 |
The Curtiss-Wright XP-55 Ascender (company designation CW-24) is a 1940s United States prototype fighter aircraft built by Curtiss-Wright. Along with the Vultee XP-54 and Northrop XP-56, it resulted from United States Army Air Corps proposal R-40C issued on 27 November 1939 for aircraft with improved performance, armament, and pilot visibility over existing fighters; it specifically allowed for unconventional aircraft designs. An unusual design for its time, it had a canard configuration with a rear-mounted engine, and two vertical tails at end of swept wings. Because of its pusher design, it was satirically referred to as the "Ass-ender".[1] Like the XP-54, the Ascender was designed for the 1,800 hp Pratt & Whitney X-1800 24-Cylinder H-engine, but was redesigned after that engine project was canceled. It was also the first Curtiss fighter aircraft to use tricycle landing gear.
Design and development
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/EL-2003-00004.jpg/220px-EL-2003-00004.jpg)
In June 1940, the Curtiss-Wright company received an Army contract for preliminary engineering data and a powered wind tunnel model.[2] The designation 'P-55' was reserved for the project. The exhaustive wind-tunnel tests that from November 1940 through January 1941 left the USAAC dissatisfied with the results of these tests.[3][4]
Accordingly, Curtiss-Wright built at their St Louis division a flying full-scale mockup they designated CW-24B.[5] The flying testbed was powered by a 275 hp (205 kW) Menasco C68-5 inline engine.[3][6][unreliable source?] It had a fabric-covered, welded steel tube fuselage with a wooden wing.[7] The undercarriage was non-retractable.[3] The canard did not carry load but only trimmed flight.[5] The CW-24B model completed its maiden flight in December 1941.[3] From November 1941 to May 1942, the Model 24B logged 169 flights at Muroc Dry Lake, California. The tests appeared to show potential.[4] The CW-24B then went to NACA at Langley Field for wind tunnel tests.[5]
On 10 July 1942, the United States Army Air Forces issued a contract for three prototypes under the designation XP-55.[4][6] Serial numbers 42-78845 through 42-78847 were assigned to the aircraft. During this time, the Pratt & Whitney X-1800 H-block sleeve valve engine was delayed, and was eventually canceled.[7] Curtiss decided to switch to the 1,000 hp (750 kW) Allison V-1710[4] (F16) liquid-cooled inline engine because of its proven reliability.[7] Armament was to be two 20 mm (0.79 in) Hispano autocannon and two 0.50 in (12.7 mm) M2 Bowning heavy machine guns.[3] During the mock-up phase, engineers switched to the 1,275 hp (951 kW) V-1710-95.[4][8] The 20mm cannons were also replaced by 0.50-in machine guns.[6]
One feature of the XP-55 was a propeller jettison lever inside the cockpit to prevent the pilot from hitting the propeller during bailout. The jettison device was invented by W. Jerome Peterson while working as a design engineer for Curtiss-Wright.[3][7]
Operational history
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Curtiss_XP-55_following_crash.jpg/220px-Curtiss_XP-55_following_crash.jpg)
Three XP-55 prototypes were built. Two were destroyed during flight testing, as a result of their propensity for sudden wing stalls.
The first XP-55 (42-78845) was completed and delivered on 13 July 1943, with the same configuration as the final prototype CW-24B. The aircraft made its first flight on 19 July 1943[3][8] from the Army's Scott Field near the Curtiss-Wright plant in St Louis, Missouri.[7] The pilot was J. Harvey Gray,[3] Curtiss' test pilot. Testing revealed the takeoff run was excessively long. To solve this problem, the nose elevator size was increased and the aileron up-trim was interconnected with the flaps so it operated after the flaps were lowered.[7]
In 15 November 1943, test pilot Harvey Gray, flying the first XP-55 (S/N 42-78845), was testing the aircraft's stall performance at altitude. Suddenly, the XP-55 inverted into an uncontrolled descent. The engine failed "making recovery impossible"[2] and it fell out of control for 16,000 ft (4,900 m) before Gray was able to parachute to safety. The aircraft was destroyed and "left a smoking hole in the ground".[4][7]
The second XP-55 (serial 42-78846) was similar to the first, but with a slightly larger nose-elevator,[7] modified elevator-tab systems, and a change from balance tabs to spring tabs on the ailerons. It flew for the first time on 9 January 1944.[4][7] All flight tests were restricted so the stall-zone was avoided; included no stalling below 20,000 ft.[5][7][9]
The third XP-55 (serial 42-78847) flew for the first time on 25 April 1944. Modifications resulting from the investigation of the crash of the first prototype were introduced during construction; the addition of four-foot wingtip extensions to improve the stall characteristics and increasing the limits of the nose elevator travel to improve recovery if a stall did occur.[2] It was the only prototype to be fitted with armament - four 0.5-inch machine guns.[5]
After the second XP-55 (42-78846) was given the same modifications as the third prototype, it underwent official USAAF flight trials between 16 September and 2 October 1944.
The third prototype XP-55 (s/n 42-78847) was lost on 27 May 1945, during the closing day of the Seventh War Bond Air Show at the Army Air Forces Fair at Wright Field in Dayton, Ohio.[7][10] After a low pass in formation with a Lockheed P-38 Lightning and a North American P-51 Mustang[7] on each wing, its pilot, William C. Glasgow, attempted a slow roll,[7] but lost altitude and crashed, sending flaming debris into occupied civilian ground vehicles on a highway near the airfield. The crash killed Glasgow and four civilians on the ground.[7][11]
In test flights the XP-55 achieved 390 mph at 19,300 feet but there were engine cooling problems.[2] In terms of overall performance, testing of the XP-55 revealed it to be inferior to conventional fighter aircraft.[4][7][12] In addition, by the end of 1944, German and British jet-powered fighters were fully operational, and the Lockheed XP-80 was about to commence operational trials with USAAF units in Italy. Development of completely new piston-engine fighter designs was regarded as redundant; further development of such aircraft was terminated, including the XP-55.
Aircraft disposition
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Air_Zoo_December_2019_016_%28Curtiss_XP-55_Ascender%29.jpg/220px-Air_Zoo_December_2019_016_%28Curtiss_XP-55_Ascender%29.jpg)
- 42-78845: crashed during vertical dive on November 15, 1943. Pilot bailed out.[13]
- 42-78846: on display at the Air Zoo in Kalamazoo, Michigan. It is on long-term loan from the Smithsonian's National Air and Space Museum in Washington, D.C.[4][7][8][14] Used for official performance tests, flying a total of 27 hours.[8]
- 42-78847: crashed during air show at Wright Field, Ohio on May 27, 1945. Pilot killed.[7][15]
Specifications (XP-55)
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/45/Curtiss_XP-55_Ascender_061024-F-1234P-006.jpg/220px-Curtiss_XP-55_Ascender_061024-F-1234P-006.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/1947_Jettison-Device-Patent.jpg/220px-1947_Jettison-Device-Patent.jpg)
Data from Green and Swanborough 1977[16] [17] Air and Space Museum [18]
General characteristics
- Crew: One (pilot)
- Length: 29 ft 7 in (9.02 m)
- Wingspan: 40 ft 7 in (12.37 m)
- Height: 10 ft 0 in (3.05 m)
- Wing area: 235 sq ft (21.8 m2)
- Empty weight: 6,354 lb (2,882 kg)
- Gross weight: 7,710 lb (3,497 kg)
- Max takeoff weight: 7,930 lb (3,597 kg)
- Powerplant: 1 × Allison V-1710-95 liquid-cooled V12 engine, 1,275 hp (951 kW)
Performance
- Maximum speed: 390 mph (630 km/h, 340 kn) at 19,300 feet (5,900 m)
- Range: 635 mi (1,022 km, 552 nmi)
- Service ceiling: 34,600 ft (10,500 m)
- Wing loading: 32.8 lb/sq ft (160 kg/m2)
- Power/mass: 0.16 hp/lb
Armament
- Guns: 4 × 0.50 in (12.7 mm) machine guns in the nose
See also
[edit]Aircraft of comparable role, configuration, and era
- Ambrosini SS.4
- Kyushu J7W Shinden
- Miles M.35 Libellula
- Northrop XP-56 Black Bullet
- SAAB 21
- Vultee XP-54
- Henschel Projekt P.75
Related lists
- List of aircraft of World War II
- List of fighter aircraft
- List of military aircraft of the United States
- Lists of air show accidents and incidents
References
[edit]Citations
[edit]- ^ Jenkins 2008. p. 8.
- ^ a b c d Rubenstein & Goldman (1974) p178
- ^ a b c d e f g h Davey, Guy (2023-03-03). "XP-55 Ascender: the Back-to-Front Fighter". PlaneHistoria. Retrieved 2023-12-02.
- ^ a b c d e f g h i "Curtiss XP-55-CS Ascender". National Air and Space Museum. Retrieved 2023-12-02.
- ^ a b c d e Bowers (1984) pp 10-11
- ^ a b c "Curtiss-Wright XP-55 Ascender". www.militaryfactory.com. Retrieved 2023-12-02.
- ^ a b c d e f g h i j k l m n o p q "World of Warbirds: Curtiss-Wright XP-55 Ascender on Apple Podcasts". Apple Podcasts. Retrieved 2023-12-02.
- ^ a b c d >"Curtiss XP-55 Ascender". Air Zoo Aerospace & Science Museum Kalamazoo, MI. Retrieved 2023-12-02.
- ^ Bowers 1979, p. 467.
- ^ Balzer 2008
- ^ Scott, Roland B. "Air Mail", Wings, Granada Hills, California, October 1978, Volume 8, Number 5, p. 10.
- ^ Green 1969, p. 65.
- ^ "XP-55 Ascender/42-78845". Joe Baugher's Serial Numbers. Retrieved: 10 May 2013.
- ^ "XP-55 Ascender/42-78846" Archived 2017-08-19 at the Wayback Machine Air Zoo. Retrieved: 10 May 2013.
- ^ "XP-55 Ascender/42-78847". Joe Baugher's Serial Numbers. Retrieved: 10 May 2013.
- ^ Green and Swanborough 1977, pp. 69–71.
- ^ Air Zoo museum XP-55 AirZoo
- ^ Curtiss XP-55 - National Air and Space Museum
Bibliography
[edit]- Balzer, Gerald H. (2008). American Secret Pusher Fighters of World War II: XP-54, XP-55, and XP-56. North Branch, MN: Specialty Press. ISBN 978-1-58007-125-3.
- Bowers, Peter M (1979). Curtiss Aircraft, 1907–1947. London: Putnam. ISBN 0-370-10029-8.
- Bowers, Peter M (1984). Unconventional Aircraft. Blue Ridge Summit, PA: Tab Books.
- Green, William (1969). War Planes of the Second World War, Volume Four: Fighters (Sixth ed.). London: MacDonald & Co. (Publishers) Ltd. ISBN 0-356-01448-7.
- Green, William; Swanborough, Gordon (1977). WW2 Aircraft Fact Files: US Army Air Force Fighters, Part 1. London: Macdonald and Jane's Publishers Ltd. ISBN 0-356-08218-0.
- Jenkins, Dennis R.; Landis, Tony R. (2008). Experimental & Prototype U.S. Air Force Jet Fighters. North Branch, MN: Specialty Press. ISBN 978-1-58007-111-6.
- McIntyre, Violet. Niagara Gazette, Niagara Falls, NY, 11 November 2004[full citation needed]
- Rubenstein, Murray; Goldman, Richard M. (1974). To Join With The Eagles : Curtiss-Wright aircraft, 1903-1965. Garden City, NY: Doubleday.
Further reading
[edit]- Balzer, Gerald H. (2014). Curtiss XP-55 Ascender. Air Force Legends. Vol. 217. Simi Valley, CA: Ginter Books. ISBN 978-0-9892-5833-3.
External links
[edit]![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- NMUSAF – Curtiss XP-55
- NASM article
- XP-55 Ascender by Joe Baugher
- Curtiss Wright XP-55 Ascender -USAAF Resource Center at warbirdsresourcegroup.org
- Dayton Air Show History
- "Flying Backwards to the Future", Popular Science, August 1945
- PlaneHistoria - XP-55 Ascender: the Back-to-Front Fighter
- The FlyingMag - The Short, Unconventional Life of the Curtiss XP-55 Ascender