Hughes XF-11

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"XF11" redirects here. For the near-Earth asteroid, see (35396) 1997 XF11.
XF-11
The second Hughes XF-11 during a 1947 test flight
Role Aerial reconnaissance
Manufacturer
Hughes Aircraft
Designer Stanley Bell, Howard Hughes, Ed West[1]
First flight 7 July 1946
Status Canceled
Primary user United States Army Air Forces
Number built 2
Developed from Hughes D-2

The Hughes XF-11 (redesignated XR-11 in 1948) was a prototype military reconnaissance aircraft designed and flown by Howard Hughes and built by Hughes Aircraft Company for the United States Army Air Forces (USAAF). Although 100 F-11s were ordered in 1943, the program was delayed beyond the end of World War II, rendering the aircraft surplus to USAAF requirements; the production contract was canceled and only two prototypes and a static test mockup were completed. During the first XF-11 flight in 1946, piloted by Hughes, the aircraft crashed in Beverly Hills, California, and was destroyed.[2][3] The second prototype was flown in 1947 but was used only briefly for testing before being stricken from inventory in 1949.[4][5] The program was controversial from the beginning, leading the United States Senate to investigate the XF-11 and the Hughes H-4 Hercules flying boat in 1946–1947.

Design and development

The F-11 was intended to meet the same USAAF operational objective as the

photographic reconnaissance, and spent several million dollars hiring additional staff and opening a new engineering office for the effort.[9][10]

Hughes campaigned the USAAF in Washington, enlisting his father's friend,

Lockheed XP-58.[13][14][15] Arnold later regretted the decision, saying that he made it "much against my better judgment and the advice of my staff" after consultations with the White House.[14][15]

A preliminary $43 million[15] contract issued on 11 October 1943 was contested by Hughes, who sought $3.6 to $3.9 million in compensation for the development of the D-2, and objected to Materiel Command's requirements for all-metal construction, self-sealing fuel tanks, and various other major design changes that undermined his contention that the F-11 was directly derived from the D-2.[15][16] The USAAF strongly objected, arguing that the D-2 project was initiated without USAAF input, and that Hughes had continuously withheld information about the aircraft.[17] In another complication, the War Production Board (WPB) wanted Hughes to build a new assembly plant near Hughes Tool Company headquarters in Houston, where labor costs were lower than in southern California. The WPB eventually relented and allowed Hughes Aircraft to use its existing Culver City, California, assembly plant, and the USAAF made some small design concessions; however, Hughes failed to secure full reimbursement and ultimately agreed to most of the design changes, notably including the elimination of Duramold. The protracted negotiations consumed the better part of ten months, and the final contract was awarded on 1 August 1944.[16] Hughes was awarded $1.6 million in reimbursement.[17]

The program was plagued by managerial and logistical delays. By early 1944, Hughes was suffering from mental strain from the demands of managing both the F-11 and

Consolidated Vultee, to manage the program, promising him full and unconditional control.[18] Perrell found Hughes Aircraft rife with inefficiency and suffering from a "complete lack of experience in the design and construction of airplanes in general." His efforts to reorganize were hindered by resistance from senior Hughes Aircraft engineers, who were accustomed to a freewheeling work atmosphere, and from Hughes Tool executives who feared that Perrell would usurp their authority over the aircraft company.[19] 21 engineers, including chief engineer Ed West, resigned in a May 1944 dispute over their offices being moved from Brea, California, to the Culver City plant.[1] The prototype's wings–subcontracted to Fleetwings–were delivered six months behind schedule in April 1945.[20] With the end of the European war in May 1945, the order for 100 F-11s was reduced to just three, a static test model and the two prototypes, and the USAAF de-prioritized the project.[20][21] The engines were delivered seven months behind schedule in September 1945.[20] By this time, Perrell had been successful in reforming the program, but there was no longer any impetus to deliver 98 production aircraft, and Hughes returned from self-imposed exile and began to interfere despite his earlier promises not to do so. Relations between the two men deteriorated and Hughes had Perrell fired in December.[22]

The XF-11 emerged as a

Pratt & Whitney R-4360-31 28-cylinder radial engines and was normally flown by a crew of two, but could accommodate a third crewmember in the central nacelle to process film in flight. Each engine drove a pair of contra-rotating four-bladed, variable-pitch propellers, which proved troublesome in testing, having a tendency to suddenly and inexplicably reverse pitch. The first prototype was conditionally accepted by the USAAF on 5 April 1946 although its electrical and hydraulic systems were incomplete. On 24 April, the aircraft was briefly flown at an altitude of 20 ft (6.1 m) over the runway, but the company decided to wait for replacement propellers before initiating formal test flights.[16]

Operational history

First prototype and Beverly Hills crash

1946 newsreel

The first prototype, tail number 44-70155, piloted by Hughes, crashed on 7 July 1946 while on its maiden flight from the Hughes Aircraft factory airfield at Culver City.[23]

Hughes did not follow the agreed testing protocol, which called for a 45-minute flight with the landing gear extended. He ordered the loading of 1,200 US gal (4,500 L) of fuel rather than 600 US gal (2,300 L) as prescribed by the USAAF, hinting at a surreptitious plan to prolong the flight.

A-20 Havoc next to the XF-11 as Hughes again lowered and raised the gear. The pair were unable to communicate directly with Hughes due to confusion about radio frequencies, but they had observed nothing amiss, so they returned to the airfield. Hughes continued flying the XF-11 in broad circles above Culver City.[25]

An hour and fifteen minutes into the flight, after onboard recording cameras had run out of film, a leak caused the right-hand propeller controls to lose their effectiveness and the rear propeller subsequently reversed its pitch, disrupting that engine's thrust and causing the aircraft to yaw hard to the right and begin descending steeply.

Beverly Hills. The third house and the aircraft were destroyed by impact and fire; Hughes was nearly killed.[3][23][29][30][31][32]

USAAF investigators concluded that, "It appeared that loss of hydraulic fluid caused failure of the pitch change mechanism of right rear propeller. Mr. Hughes maintained full power of right engine and reduced that of left engine instead of trying to fly with right propeller windmilling without power. It was

Wright Field's understanding that the crash was attributed to pilot error,"[33] yet Hughes successfully brought suit against Hamilton Standard for the malfunctioning contra-rotating blades in the right propeller.[21] The crash was dramatized in the 2004 biographical film The Aviator
.

Second prototype

The second prototype, 44-70156, was fitted with conventional single four-bladed propellers, and was flown by Hughes on 5 April 1947.

Muroc Dry Lake for the flight, fearing the repercussions of another crash in a populated area.[26]

This test flight was uneventful, and the aircraft proved stable and controllable at high speed. It lacked low-speed stability, however, as the ailerons were ineffective at low altitudes. When the USAAF evaluated it against the Republic XF-12, testing revealed the XF-11 was harder to fly and maintain, and it was projected to be twice as expensive to build.[27] An F-12 production order was issued, but the USAAF ultimately canceled it in favor of the RB-50 Superfortress and Northrop F-15 Reporter, both of which had similar long-range photo-reconnaissance capability and were available at a much lower cost.

The

sunk costs from the D-2.[37]

Senate investigation

Main article: Truman Committee

From 1946-1947, the

Pan American World Airways, which Brewster backed.[39] The committee revealed that John Meyer had spent $169,661 (equivalent to $2,987,339 in 2023) entertaining Elliott Roosevelt and other USAAF officers overseeing reconnaissance aircraft procurement.[40] On 4 August 1947, Meyer and Roosevelt testified before the committee and denied any wrongdoing or improper influence.[41] Howard Hughes subsequently testified before the committee and is generally thought to have successfully deflected criticism of his company's alleged mismanagement of the F-11 and H-4 contracts.[42]

Specifications (XF-11)

The second XF-11

Data from Jane's all the World's Aircraft 1947[43]

General characteristics

  • Crew: 2, pilot and navigator/photographer
  • Length: 65 ft 3 in (19.9 m)
  • Wingspan: 101 ft 5 in (30.9 m)
  • Wing area: 983 sq ft (91.3 m2)
  • Aspect ratio: 10.46
  • Airfoil: NACA 66(215)-216
  • Empty weight: 37,100 lb (16,828 kg)
  • Gross weight: 47,500 lb (21,546 kg) (4,000 mi (3,500 nmi; 6,400 km) range)
  • Max takeoff weight: 58,315 lb (26,451 kg) (5,000 mi (4,300 nmi; 8,000 km) range)
  • Powerplant: 2 ×
    Pratt & Whitney R-4360-31 Wasp Major
    28-cyl. air-cooled radial piston engines, 3,000 hp (2,200 kW) each
  • Propellers: 8-bladed
    Hamilton Standard Hydromatic
    contra-rotating propellers

Performance

  • Maximum speed: 450 mph (720 km/h, 390 kn) at 33,000 ft (10,000 m); 295 mph (256 kn; 475 km/h) at sea level
  • Service ceiling: 42,000 ft (13,000 m)
  • Rate of climb: 1,000 ft/min (5.1 m/s)
  • Time to altitude: 33,000 ft (10,000 m) in 17.4 minutes
  • Wing loading: 59.3 lb/sq ft (290 kg/m2) (5,000 mi (4,300 nmi; 8,000 km) range)

See also

Related development

Aircraft of comparable role, configuration, and era

Related lists

  • List of military aircraft of the United States

Notes

  1. ^ Quoting Eaker's Nov. 1947 testimony to the Senate.[35]

Footnotes

  1. ^ a b Francillon 1990, p. 74.
  2. ^ Parker 2013, pp. 49–51.
  3. ^ a b Bartlett & Steele 2004, p. 140.
  4. ^ a b Francillon 1990, pp. 76–77.
  5. ^ a b Bartlett & Steele 2004, p. 158.
  6. ^ Winchester 2005, p. 222.
  7. ^ Bartlett & Steele 2004, p. 107.
  8. ^ Francillon 1990, p. 52.
  9. ^ Bartlett & Steele 2004, pp. 107–109.
  10. ^ Francillon 1990, pp. 55, 58.
  11. ^ Bartlett & Steele 2004, p. 109–112.
  12. ^ Bartlett & Steele 2004, pp. 125–126.
  13. ^ Francillon 1990, pp. 73–74.
  14. ^ a b Hansen 2012, p. 541.
  15. ^ a b c d Bartlett & Steele 2004, p. 127.
  16. ^ a b c Francillon 1990, pp. 74–75.
  17. ^ a b Bartlett & Steele 2004, p. 130.
  18. ^ Bartlett & Steele 2004, pp. 130–131.
  19. ^ Bartlett & Steele 2004, pp. 135–136.
  20. ^ a b c Francillon 1990, p. 75.
  21. ^ a b Dietrich & Thomas 1972, pp. 187, 193, 197.
  22. ^ Bartlett & Steele 2004, p. 136.
  23. ^ a b "Crash of the XF-11." check-six.com. Retrieved: 16 June 2010.
  24. ^ a b Bartlett & Steele 2004, p. 138.
  25. ^ a b c d Bartlett & Steele 2004, p. 139.
  26. ^ a b c d e Francillon 1990, p. 76.
  27. ^ a b Winchester 2005, p. 223.
  28. ^ Bartlett & Steele 2004, pp. 139–140.
  29. ^ "Howard Hughes, millionaire airplane designer, fights for life". Oxnard Press-Courier. (California). United Press. 8 July 1946. p. 1.
  30. ^ "Hughes injured in plane crash". Spokesman-Review. (Spokane, Washington). Associated Press. 8 July 1946. p. 1.
  31. ^ "Howard Hughes given "50-50" life chance". Spokesman-Review. (Spokane, Washington). Associated Press. 9 July 1946. p. 1.
  32. ^ "Hughes puts life in peril by activity". Oxnard Press-Courier. (California). United Press. 9 July 1946. p. 1.
  33. ^ USAAF Materiel Command to Gen. Spaatz, 16 August 1946, at F-11 project file at Air Force Historical Research Agency
  34. ^ Bartlett & Steele 2004, p. 144.
  35. ^ a b Hansen 2012, p. 562.
  36. ^ Fort Walton, Florida, "New Ship At Eglin", Playground News, 30 December 1948, Vol. 3, No. 48, p. 1.
  37. ^ Francillon 1990, p. 77.
  38. ^ Hansen 2012, pp. 530–536.
  39. ^ a b Bartlett & Steele 2004, p. 146.
  40. ^ Bartlett & Steele 2004, p. 147.
  41. ^ Bartlett & Steele 2004, pp. 149–150.
  42. ^ Bartlett & Steele 2004, p. 153.
  43. ^ Bridgman 1947, p. 172c.

Bibliography

Further reading

  • Barton, Charles (August 1982). "Howard Hughes and the 10,000 ft. Split-S". Air Classics. 18 (8).

External links

Wikimedia Commons has media related to Hughes XF-11.
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