By Al Moyers, Headquarters Air Force Operational Test and Evaluation Center Director of History and Research
/ Published June 20, 2007
KIRTLAND AIR FORCE BASE, N.M. -- On July 13, 2006, the Air Force Operational Test and Evaluation Center's (AFOTEC) CV-22 test director reported that the team had completed the last test event for the operational utility evaluation of the CV-22 Osprey--the Air Force's version of the multi-service, multi-mission, medium-lift, tilt-rotor aircraft. For more than two decades AFOTEC personnel have been involved in the development of the V-22. Following the cancellation of the Marine Corps replacement assault transport helicopter (HXM) program, Deputy Secretary of Defense Frank C. Carlucci directed the Services in December 1981 to review vertical/short takeoff and landing (V/STOL) technology to establish a joint aircraft program for a medium-lift V/STOL aircraft. Secretary Carlucci specifically called upon the Services to take advantage of tilt-rotor technology.
The Services program review initiated the Joint Services Advanced Vertical Lift Aircraft (JVX) project with the U. S. Army as the lead agency. As initially envisioned JVX was to satisfy the Marine Corps' HXM requirements as well as provide a new special electronic mission aircraft (SEMA) for the Army, a combat search and rescue aircraft for the Navy and Air Force, and an Air Force special operations aircraft. The Service chiefs anticipated that the then-planned acquisition of 1,086 JVX aircraft would reduce or replace a number of aircraft and helicopters, including the Air Force's HH-53 and HH-60 helicopters.
The Secretaries of the Army, Navy, and Air Force signed a memorandum of understanding in June 1982 on JVX development. Due to the Marines having the largest requirement, the JVX program agreements established the Marine Corps version as the JVX baseline configuration and all other requirements as "variants." Therefore, in December 1982, the Office of the Security of Defense transferred JVX program management to the Department of the Navy. The Navy released a request for purchase for the preliminary design phase of the JVX program in January 1983. Bell Helicopter-Textron, Inc., and Boeing Vertol (today's Boeing Helicopter) replied to the Navy's request. The Navy contracted a Bell-Boeing joint venture to develop the preliminary design. In April-May 1983 the Service's assistant secretaries for research and development signed a memorandum of understanding related to the development of the V-22 in which each of the Services where charged with "accomplishing its operational test and evaluation program as a separate project related to but not included within the common aircraft development project."
The Army reviewed its overall aircraft mission requirements and decided in 1983 to withdraw from its unique variant of JVX development and decided it would purchase the Marine's baseline aircraft, even though it had invested several decades into tilt-rotor technology. Concurrently, the Air Force reduced its requirement for the JVX from 200 to 80, with the aircraft to be used solely for special operations. In less than two years, the total anticipated JVX buy dropped by more than 170 aircraft. In 1985 the Navy issued a request for Full Scale Development. That same year the program was officially named the V-22 Osprey and AFOTEC planners were fully engaged in V-22 test development.
The helicopter's vertical take off and landing capability had proved its military value in the closing days of World War II. But, the conventional helicopter's fixed vertical main rotor limits its forward flight performance. The need, as early as World War II, for a military aircraft that could combine a vertical takeoff and landing capability with the forward speed of a traditional fixed-wing aircraft led to military funding of both tilt-wing and tilt-rotor trials. Tilt-wing technology never became a viable concept to replace the helicopter. Tilt-rotor technology was promising.
Tilt-rotor technology has taken more than a half-century to develop to a level of maturity that is "effective and suitable" for operational military employment. During a forum at Los Alamos National Laboratory in 1998, Dr. Hans M. Mark, Secretary of the Air Force from 1979 to 1981, told the assembled group of scientists and engineers, "It's a good thing tilt-rotor technology, around since the 1940s, didn't go away." Secretary Mark became involved in the development of tilt-rotor technology in 1969 when he was appointed director of the National Aeronautical and Space Administration's (NASA) Ames Research Center in California. He continued his promotion of the technology throughout and after his tenure as Secretary of the Air Force.
A number of pioneers were exploring tilt-rotor concepts as early as the first half of the twentieth century. American engineer Henry Berliner experimented with a tilt-propeller craft in the late 1920s that could attain a forward speed nearing 40 miles per hour after a vertical take-off. The U.S. Patent Office issued George Lehberger a patent for his "Flying Machine" in September 1930. Its design incorporated the features of a modern tilt-rotor aircraft. British inventor, E. L Baynes, who later was instrumental in the development of the sweep-wing, patented a design in 1938 for his "Heliplane." The Baynes "Heliplane" design was very similar to that of the V-22.
Tilt-rotor development, sometimes referred to as a "convert-o-plane," continued throughout the 1940s. In 1947, the Transcendental Aircraft Company began work on its Model 1-G tilt-rotor aircraft. The Air Force and Army began funding Transcendental's work in 1952. The Model 1-G flew more than 100 flights. The craft first transitioned from vertical to horizontal flight in December 1954, in what is considered by many tilt-rotor enthusiasts to be the first truly successful modern tilt-rotor demonstration. The Air Force, however, lost interest in Transcendental's projects in favor of the Bell XV-3 after the frail Model 1-G was destroyed in an accident in July 1955.
In 1951, the Air Force and Army requested proposals for a Convertible Aircraft Program to develop a V/STOL aircraft. Bell Helicopter, McDonnell Aircraft, and Sikorsky Aircraft companies responded. The Air Force and Army funded the McDonnell and Bell proposals for further development, although their prototypes differed greatly.
Bell Helicopter started working on tilt-rotor technology in the late 193Os. Bell's Model 200 tilt-rotor aircraft, designated the XV-3, was built in 1953 and flew until 1966, proving to most observers the fundamental soundness of the tilt-rotor concept. The Bell XV-3 had a single engine mounted in the fuselage to drive two movable rotors mounted at the tips of small wings.
In contrast, McDonnell engineers used a single rotor for vertical lift and a pusher propeller for forward thrust on its compound helicopter designated the XV-1. The XV-1 took off vertically with its vertically-mounted rotor and transitioned to forward flight by diverting engine power from the rotor to the pusher propeller when the craft exceeded the stall speed of its stub wings. In the late 1950s the XV-1 was superior to conventional helicopters, but by 1961, improved rotor systems gave conventional helicopters the speed to match and eventually surpass the XV-1. Soon, industry and the Services abandoned the concept of fixed, rather than tilting, rotor technology for V/STOL aircraft.
"By the time I got to [be Director of the] Ames Research Center in 1969," Secretary Marks stated at the 1998 Los Alamos meeting, "people there were wondering what the next step [in tilt-rotor technology development] was." In 1971, Mark proposed to the NASA and the Army that the tilt-rotor plane should be further developed. In 1972, with NASA and Army funding, Bell Helicopter began development of the Model 301, a twin-engine tilt-rotor research aircraft the Army designated the XV-15.
Secretary Marks further commented, "When I moved from Ames [Research Center] to the Pentagon [in 1977 as Undersecretary of the Air Force], I tried to sell the program, but there were no takers. For the next three or four years, nothing happened." In 1981 Secretary of the Navy John Lehman along with other Department of Defense officials observed the XV-15 tilt-rotor demonstration at the Paris Air Show, after which Secretary Lehman proposed the Navy should pursue tilt-rotor technology to replace aging Marine helicopters vice another conventional helicopter development.
The Defense Systems Acquisition Review Council, forerunner of today's Defense Acquisition Board, approved acquisition Milestone II for the JVX program in May 1986. The program entered Full Scale Development with a $1.7 billion contract to the Bell-Boeing joint venture. In 1987 the Pentagon reported it would purchase 913 V-22s for the Army, Navy, Marines, and Air Force at a cost of in excess of $33 billion, an average aircraft cost of approximately $36 million. However, the Army totally pulled out of the JVX program in 1988 citing the growing expense of the program and its other procurement priorities. At that point, the Pentagon reduced the scope of the program to a total of 657 V-22 aircraft: 552 for the Marines, 50 for the Navy, and 55 for the Air Force.
President George H. W. Bush took office in January 1989. The Osprey took its first flight on March 19, 1989. In April 1989 Secretary of Defense Richard B. Cheney withdrew Pentagon support for the program as part of the Bush Administration's cutting of "wasteful spending" on "unproven technology." Secretary Cheney requested no funding of the V-22 program again in 1990, 1991, and 1992, asking each year for Congress to fund instead a cheaper medium-lift helicopter. Secretary Mark recalled, "We [supporters of the V-22, known my some as the Tilt-Rotor Coalition,] had to figure out a way to keep the program alive. We did so through Congress." Congress continued to provide money for continued development of the V-22 while prohibiting the monies for research or development on any craft to replace the Osprey. "The program was dormant, but alive," Mark concluded.
The V-22 program suffered additional setbacks in the early 1990s. The fifth V-22 prototype crashed on June 11, 1991, during its first flight. Fortunately, there were no fatalities. However, a second prototype V-22 crashed on June 20, 1992, killing the three Marines and four civilian contractors onboard.
In 1993 President William J. Clinton took office and brought with him an administration supportive of the V-22. The Fiscal Year 1994 appropriations legislation added funds to restart V-22 development. In December 1994, following an extended period of review of operational requirements and medium-lift alternatives, the Defense Acquisition Board concluded the Milestone Il+ review and approved the Engineering, Manufacturing, and Development phase of the program. The Board authorized continued developmental testing of the prototype aircraft and a Low Rate Initial Production of four additional aircraft. As the V-22 developed, the program requirements were (re-)stated in an April 1995 Joint Multi-Mission Vertical Lift Aircraft (JMVX) Operational Requirements Document. This document called for an aircraft that would provide the Marine Corps and Air Force the ability to conduct assault support and long-range, high-speed missions requiring vertical takeoff and landing capabilities.
After transition of the V-22 program to the Engineering, Manufacturing, and Development phase, the Multi-Service Operational Test Team, in which AFOTEC personnel participated with members of the Navy's Operational Test and Evaluation Force (OPTEFOR), conducted four periods of operational testing. The first three periods--OT-IIA from May to July 1994, OT-IIB from June to October 1995 and OT-IIC from October 1996 to May 1997--involved testing prototype aircraft developed under the Full Scale Development phase of the program. While these aircraft had acknowledged shortcomings with respect to weight and payload, this testing provided early opportunity to explore the use of a tilt-rotor aircraft to perform operationally oriented military missions. In the joint OPTEFOR-AFOTEC reports following each of these initial evaluations, the testers concluded that the V-22 was potentially operationally effective and potentially operationally suitable.
By 1997, the Pentagon's revised V-22 budget called for production of 523 Ospreys, less than 50 percent of the original production figure. The first V-22 built to production standards made its initial flight in February 1997 and was delivered to the Navy in March 1997. The test team conducted the fourth operational test phase, OT-IID, from September to October 1998 during which the team evaluated a production representative MV-22. In the joint OPTEFOR-AFOTEC report, the testers again concluded that the V-22 was potentially operationally effective and potentially operationally suitable although the report highlighted areas of concern for continued development including poor Mean Flight Hours between Aborts and Maintenance Man-Hours per Flight Hour, which were both listed as significant risk areas that needed to be further evaluated.
In 1999 an MV-22 was delivered to Bell Helicopter Textron's Arlington, Texas, facility to be remanufactured into the first Air Force CV-22. The first of two MV-22-converted-to-CV-22 aircraft arrived at Edwards Air Force Base, California, on September 18, 2000. To the casual average observer, the most visible difference between the Air Force and Marine version of the Osprey is the four-person crew, consisting of two pilots and two flight engineers, vice the MV-22's three-person crew. The CV-22 also includes unique systems such as multi-mode radar for terrain following and terrain avoidance, auxiliary fuel tanks, and an integrated electronic warfare suite.
The third V-22 crash occurred at Tucson, Arizona, on April 8, 2000. Nineteen Marines were killed. Following a two-month stand-down in flight operations, the MV-22 test team concluded the next operational evaluation, OT-IIE, in June 2000 in preparation for the Milestone III decision, Full Rate Production. The MV-22 entered this evaluation with reportedly fewer deficiencies than any aircraft in the history of naval aviation. The joint OPTEFOR-AFOTEC report stated the MV-22 was operationally effective and operationally suitable for land-based operations but, not for ship-based operations until additional evaluation of the system designed to fold and stow the prop-rotors and wings; however, the report recommended fleet introduction. In November 2000 the MV-22 Osprey's improved Blade Fold Wing Stow system was successfully demonstrated at sea. The team report also concluded that the CV-22, which was not actually tested during this OPEVAL, was potentially operationally effective and potentially operationally suitable and recommended continued development.
In his November 2000 Beyond-Low Rate Initial Production report to Congress, the Department of Defense's Director of Operational Test and Evaluation reported that the MV-22, without making the distinction between land- and ship-based operations, was not operationally suitable. According to the DOT&E report, the MV-22 demonstrated marginal mission reliability, excessive maintenance manpower and logistic support requirements and inadequate availability, interoperability, human factors documentation, and diagnostics capabilities.
On December 11, 2000, an MV-22 crashed--the second MV-22 crash during the year; the fourth since the V-22 had begun flying. The Defense Department grounded the V-22 and postponed the Full Rate Production decision until the reasons for the crashes were determined and eliminated. Independent panels recommended numerous design improvements to hydraulic, electrical, and software systems be initiated prior to the V-22 returning to flight. On December 21, 2001, Pete Aldridge, Undersecretary of Defense for Acquisition, Technology and Logistics, announced that the troubled V-22 would go through a two-year flight test program to further explore potential problem areas, including combat maneuverability, formation flying, and refueling. The V-22 again returned to flight on May 29, 2002.
The first Block A MV-22, which incorporated software modifications, weight reduction initiatives, a redesigned nacelle and other safety of flight features, was delivered on August 20, 2003. From May to July 2004 the multi-service test team conducted a risk mitigation operational assessment, OT-IIF, of the Block A Osprey. The joint OPTEFOR-AFOTEC report concluded that the V-22 remained effective and suitable for continued development. The Block A MV-22 operational evaluation, OT-IIG, was conducted from March to June 2005. Again, the joint OPTEFOR-AFOTEC report released in August 2005 concluded the MV-22 was operationally effective, operationally suitable, and recommended the craft for fleet introduction. The Defense Acquisition Board approved Milestone III on September 28, 2005, authorizing Full Rate Production of the Osprey. The first four production representative CV-22 aircraft were in place at Kirtland Air Force Base, New Mexico, in March 2006. The CV-22 test team's operational utility evaluation concluded in July 2006 to report the CV-22's preparation for proceeding as a training platform.
As the twenty-first century began, the Osprey's future was uncertain. Between 1991 and 2000 four V-22s crashed --more than a quarter of the V-22 inventory to that time--killing 26 Marines and four civilians. By 2001, the cost per V-22 had grown from the original 1980s estimate of $24 million to today's estimate of $80 million-plus per unit by the time the procurement of the V-22 is complete. With the growing cost of the program, the required number of aircraft has reduced by more than 50 percent--from 1,086 in 1982 to 458 in 2006. The Air Force has reduced its purchase of the CV-22 by 75 percent, from an initial planned buy of 200 craft to today's procurement schedule of 50 CV-22s.
President George W. Bush took office in January 2001 having campaigned like his father to reduce wasteful Pentagon spending. Most pundits presumed reductions would include the V-22 which Vice President Cheney had tried unsuccessfully to end when he was Secretary of Defense during the first Bush Administration. Critics continue to challenge the veracity of the V-22. In their joint August 2006 report, authors from the Center for American Progress and the Lexington Institute argue that the Marines should use their current budget authority to purchase medium-lift helicopters rather than placing hope on purchasing the planned MV-22s.
But, like its namesake, the Osprey survives; and, thus, AFOTEC's CV-22 test team continues the command's more than two decades of involvement with the program. Combat-ready CV-22s are planned for delivery to the 16th Special Operations Wing in 2007. The CV-22 initial operational test and evaluation is scheduled for 2008. The Air Force's Ospreys are programmed to achieve initial operational capability in 2009.