Staff Writer (Updated: 4/6/2016):
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.