In 1981, the United States Department of Defense enacted the "Joint-Service Vertical Take-Off/Landing Experimental" (JVX) program intending to secure a specialized aircraft with vertical take-off and horizontal flight capabilities beyond that of a traditional. The initiative was related to the failed 1980 Iran Hostage Crisis rescue attempt (Operation Eagle Claw) that left eight American service personnel dead and wreckages strewn across the Iranian desert. As such, the American military sought to right the wrongs of old and procure a multi-faceted aircraft design capable of short-field operations with exceptional hauling capabilities for the class. The United States was still locked in a war of words and technology with the Soviet Union in the Cold War which would last until 1991. As such, defense spending was rather open to vastly new technologies to provide American with the upper hand in future war. While the United States Army initially headed the JVX program requirements, the craft would eventually stock the inventory of the US Marine Corps and United States Air Force.
From the start, various concerns lent their interest to the JVX program including foreign participants. However, it would become a joint development venture of Bell Helicopter and Boeing Vertol that would see the JVX to fruition. Bell Helicopter Textron had already developed the XV-15 tiltrotor technology demonstrator, which had seen its first flight on May 3rd, 1977, and proved the VTOL-to-horizontal-flight concept sound. The design allowed for take-off in much the same way as a conventional helicopter while its tiltrotor functionality allowed the rotors to be lowered in a "puller" arrangement and, thusly, propell the aircraft through the sky as a conventional fixed-wing type. The benefits of such a configuration were largely in speed and range. Two XV-15A prototypes were built and tested through NASA. The Bell Boeing submission was, in effect, an enlarged form of the successful XV-15 series prototype. The submission was officially accepted and six flyable prototypes were ordered (later reduced to five).
On January, 15th, 1985, the US DoD formally assigned the designator of "V-22" and nickname of "Osprey" to the JVX program product. The first V-22 prototype was unveiled in May of 1988. However, the United States Army left the program during the year due to rising costs and short-term commitments elsewhere, leaving the USMC and USAF as primary players in 1983. The program then suffered through the requisite "Political Hell" in which several moves nearly killed the project (the program was nearly cancelled in full in 1992). However, there proved enough evidence of the feasibility, and capabilities inherent in the V-22 to proceed with the project for the interim. First horizontal flight of an MV-22 (designation for USMC V-22s) was recorded on March 19th, 1989 to which a vertical flight then followed on September 14th of that year. Sea trials were conducted on the deck of the USS Wasp in December of 1990.
Despite the progress, the V-22 program saw the loss of the fourth and fifth prototypes to accidents. This forced Bell Boeing back to the engineering boards in an effort to refine the initial V-22 design. The delay lasted from 1992 to 1993 to which the modified airframe emerged as the "V-22B" (resulting in original V-22s being redesignated to "V-22A"). The V-22B was utilized in a myriad of additional testing from thereon. An evaluation prototype was sent to the Naval Air Warfare Test Center in Maryland in 1997.
The V-22 faced two more accidents that claimed the life of 19 marines during April and December of 2000 (30 fatalities in all would be attributed to V-22 development). The much-publicized accidents pushed its formal evaluation period to June of 2005 while additional safety measures were implemented via improved hydraulics and updated system software. By this time, the program's developmental costs had ballooned to $27 billion from the original $2.5 billion projected. Serial full-rate production was granted on September 28th, 2005 to which the V-22 was introduced into American military service on June 13th, 2007. Its primary users became the United States Marine Corps followed by the United States Air Force. At the time of its inception, the V-22 became the world's first operational tiltrotor design anywhere in the world - another American aviation "first".
Some 458 V-22s were ordered (originally 552 was mentioned) with 360 expected to enter USMC service (MV-22B) and 50 aircraft slated for the USAF (CV-22) while the US Navy may receive as many as 48 examples (HV-22). The US Navy is entertaining replacement of their long-running Grumman C-2 "Greyhound" carrier aircraft with navalized HV-22 Ospreys in the Carrier Onboard Delivery (COB) role. Evaluation began in October of 2012. HV-22s will utilize a special wing assembly system in which the entire unit rotates to sit over the running length of the fuselage. Additionally, two of its rotor blades on each engine nacelle will collapse via hinges. In this form, the vehicle will be made more compact for space-strapped aircraft carriers. Interestingly, the USN initially passed on an HV-22 Search & Rescue variant in 2001, electing the MH-60S series instead. USAF breeds can make use of long-range fuel tanks and mount terrain-following radar for special forces use. All production V-22s are slated to received an avionics upgrade in the next several years provided by Raytheon through the designated "Block C" initiative. Several USMC mounts have already been delivered with said upgrades promising increased performance and improved situational awareness.
Externally, there is no aircraft like the Osprey in the modern skies. The cockpit consists of a side-by-side seating arrangement with framed canopy windscreen allowing for above, side and forward views of the action behind a short, sloping nosecone. The passenger/cargo cabin is directly aft of the cockpit with access doors along the sides of the forward fuselage. The fuselage carries a noticeably bulged lower sides while the straight-wing appendages are seated atop the roof at amidships. Each wing root manages a positional engine nacelle which can face upwards for (take-off, landing and hovering) or tilt horizontally to direct power for forward flight as needed. Each engine powers a large, three-bladed composite rotor assembly. The wing root houses a cross-shaft system that allows both propellers to be powered in the event of emergency power loss to one engine. The empennage of the craft is raised to allow access to the powered cargo ramp at rear. The tail is capped by a twin vertical tail arrangement and large-area horizontal tail plane. The undercarriage is fully-retractable and consists of a pair of double-tired main legs and a double-tired nose leg. The standard operating crew of a V-22 is four personnel and includes two pilots and a pair of flight engineers. Up to 24 seated ("crash-worthy" seats) passengers or 32 standing infantry can be transported. In lieu of personnel, the aircraft can haul up to 20,000lbs of internal cargo or 15,000lbs of external cargo (such as an underslung M777 howitzer artillery). A single four-wheeled JEEP-type vehicle (USMC "Growler" ITV) can also be transported within the fuselage.
The MV-22B (USMC) is powered by 2 x Rolls-Royce Allison T406/AE 1107C-Liberty turboshaft engines outputting at 6,150 horsepower each. Each engine is housed in a streamlined nacelle at the end of the wing assembly. Maximum listed speed is 316 miles per hour with a cruise speed of 277 miles per hour. Operational range is 1,000 miles with a ferry range of 2,230 miles. Rate-of-climb is approximately 2,300 to 4,000 feet per second. A refueling probe is affixed to the front right side of the nose for in-flight refueling capabilities and, thusly, longer operational ranges as required.
As can be expected, the Osprey cockpit is a highly-functional, all-digital "glass" arrangement complete with two Multi-Function Displays (MFDs) dominating the forward instrument panel of each pilot's position. Control is through a central stick (between the knees) with side-mounted throttle handle (to the outboard side of either seat). A third MFD is afforded to the central console and a myriad of push-button keys control various mission and flight systems. An in-flight autopilot is standard as is FLIR, ILS, GPS, INS, VOR and TACAN systems. Flight controls are assisted by fly-by-wire software which includes quick-reaction, computer-assisted data processing. A multi-mission radar stem protrudes from the front-left nosecone with a pilot night vision system mounted under the chin.
While not inherently armed in the basic transport role, the Osprey has since been outfitted with a machine gun on a flexible mounting at the rear loading ramp (7.62mm M240 GPMG or 12.7mm M2 Browning HMG). This requires the loading door to remain open during firing but provides a tremendous field of fire and engagement of passing ground targets. A 12.7mm GAU-19 three-barreled Gatling gun was proposed for belly-mounting on V-22s (remote-controlled by a gunner within the fuselage). Such-equipped Ospreys were evaluated under operational conditions in Afghanistan throughout 2009 but found lacking though the weapon arrangement may yet reappear in future V-22 developments.
For the USMC, the MV-22 was selected as the direct replacement for its long-running Boeing Vertol CH-46 Sea Knight tandem rotor transport helicopter (in service since 1964). The first MV-22 squadron was activated on March 3rd, 2006 (as VMM-263). The "MV-22C" designation marks upgraded software MV-22s. CH-46 replacement is still ongoing (2012) and will last several years before the mount is officially retired from USMC service and completely replaced by MV-22s.
With the American commitment in both Afghanistan and Iraq, MV-22s have seen combat operations since September of 2007. Overall, operational service has been reportedly good considering the technological reach of these aircraft. It is noteworthy that none have been lost to enemy ground fire (including shoulder-launched missiles) and all missions related to Osprey operations have been a success with qualities such as its speed and range being cited. Several issues primarily related to its ship-born functionality and pilot situational awareness were noted though this becomes a natural part of the "teething" process concerning new technologies as a whole. As such, overall reliability rates have been deemed low (roughly 60%) while accident rates themselves have stayed relatively low (six deaths recorded during formal operations). To date, the V-22 has been used in the cargo transport, infantry transport, artillery hauling and search and rescue roles while also partaking in humanitarian relief efforts where conventional vehicles dare not tread.
USAF V-22s are designated as "CV-22B" and the first was received on March 20th, 2006. CV-22s have since been utilized for humanitarian assistance and at least six have been operationally serving in the combat theater of Iraq.
Numerically, the USMC remains the largest V-22 operator in the world with the USAF coming in a distant second. In 2012, the USMC operated 97 MV-22s with the USAF managing 13 CV-22s and the latter serving strictly with Special Operations. VMMT-204 is the dedicated training squadron for USMC aviators.
Bell Boeing has proposed additional variants to the base V-22 line including the EV-22 as an Airborne Early Warning and Control (AEWC) platform. Some interest of this type was shown by the British Royal Navy but never enacted upon. The SV-22 is a proposed Anti-Submarine Warfare (ASW) version for the US Navy outfitted with specialized instrumentation, equipment and assumed dipping sonar capability.
To date (2012), 160 Ospreys have been produced at a cost of roughly $70 million per system. While no foreign operators of the V-22 exist as of yet, there is potential interest from several overseas parties (Canada and UAE being mentioned). It is still possible that the US Army may re-enter the V-22 arena when it seeks a replacement for its aging UH-60 Blackhawk line in time.