THE BELL BOEING V-22 OSPREY - BRIDGING THE GAP
By Willie bodenstein
The need for an aircraft that could bridge the gap between the helicopter and fixed wing has long been identified. Throughout the years numerous attempts has been made to design and build an aircraft that had the functionality of a conventional helicopter with the long-range, high-speed cruise performance of a turboprop aircraft. The Bell Boeing V-22 Osprey finally bridged that gap. The Osprey is not only an engineering marvel but also the first successful Tiltrotor to be taken into service and first aircraft designed from the ground up to meet the specifications of all four branches of the United States Department of Defence.
Following the failure of the Iran hostage rescue fiasco in 1980 the United States Department of Defence Joint Services in 1981 identified the need for "a new type of aircraft that could not only take off and land vertically but also could carry combat troops, and do so at speed." The Joint-service Vertical take-off/landing experimental aircraft program (JVX) started the same year. The road from prototype to production model was long and arduous.
In 1982 a request for proposal (RFP) was issued for preliminary design work. Almost all of the rotor craft helicopter manufacturers expressed interest. Bell Helicopters and Boeing Vertol submission for an enlarged version won the day and in April 1983 they were contracted to start work.
Six prototypes were completed by 1989 with the first flight in helicopter mode taking place on 19 March 1989 and on 14 September of the same year in fixed mode. First see trials were successfully conducted in December 1990 by the third and fourth prototypes. The following year however tragedy struck when the fourth prototype crashed followed by the fifth in 1992.
Extensive redesign that incorporated safety improvements and weight reduction took place between October 1992 and April 1993. V-22B, the redesigned version resumed test flights in 1993 and in June 1994 Bell Boeing was awarded the contact for engineering and manufacturer development. Flight testing continued until 1997 with the remaining original prototypes that were upgraded to V-22B standard.
In 2000 tragedy again struck when two V-22B's crashed, this time killing 19 marines. All Ospreys were grounded until the cause of the crashes was established. In 2005 the final operational evaluation were completed by then however the cost of the program had risen from a budgeted USD 2.5 billion in 1986 to USD 30 billion in 1988. Production cost of the technically complicated Osprey was by then estimated to be in the region of USD60 million compared to the USD35 million of 35CH-53E heavy lift helicopter that had a greater payload than the Tiltrotor.
The project had a torrent time in the US Congress from 1989 to 1992 with various initiatives to curtail or halt further financing. As late as 1992 Dick Cheney the then Secretary of Defence endeavoured to halt finance and in so doing bring to a halt to the project. Fortunately he was over ruled by Congress.
The Osprey today operates in the multi-mission environment. Its missions amongst other can include medevac, search and rescue, amphibious assault, special ops infiltration and combat support. Able to carry 24 fully equipped combat troops, 20,000 pounds or up to 15,000 pounds of external cargo at almost twice the speed of a helicopter and with an operational range significantly greater than that of the conventional rotorcraft the Osprey has proofed the feasibility of the Tiltrotor concept.
In active service in Afghanistan the V-22 is not only changing the way the US Marine Corps operate but has flown more than 100, 000 hours most of which in the unforgiving terrain in the Helmand province. The Osprey's high speed, high altitude capability and less noise make the V-22 less susceptible to be hit by ground fire than a conventional rotorcraft. It is probably the safest rotorcraft operated by the Marines having suffered only one accident in the more than decade of operational service in deployment to Iraq, Afghanistan and Haiti. The only fatal accident occurred during a combat mission in Afghanistan. Despite being hit and colliding with the ground at high speed 16 of the 20 Marines on board survived.
During the Libyan conflict a USAF Pilot was downed. An Osprey was despatched and the high speed and vertical take-off and landing ability of the V-22 successfully retrieved the pilot within 90 minutes. The Osprey had many detractors during it protracted development period but it has proved its critics wrong.
V-22 OSPREY TECHNICAL SPECS
Two Rolls Royce AE1107C turbo shaft engines 6,150 shaft horsepower.
Three bladed 38.08 feet (11.6 meter diameter) graphite/fibreglass rotor system with automatic blade folding.
Max speed: 250 kts (4630km/h)
Service ceiling: 25, 000 feet (7,620 m)
Service ceiling, one engine inoperative: 10,300 feet (3,139 m)
Unrefuelled mission radius with 24 troops: 390 nm (722 km)
Cockpit, crew seats: 2/3
Takeoff, vertical, max: 52,600 lbs (23,859 kg)
Cargo hook, single: 10,000 lbs (4,356 kg)
Cargo hook, dual: 15,000 lbs (6,147 kg)
Dimensions -- Internal
Length, max: 20.8 feet (6.34 m)
Width, max: 5.7 feet (1.74 m)
Height, max: 5.5 feet (1.67 m)
Dimensions -- External
Length, fuselage: 57.33 feet (17.48 m)
Width, rotors turning: 84.6 feet (25.78 m)
Height, nacelles fully vertical: 22.1 feet (6.74 m)
MV-22: 1,721 gals (6,513 litres)
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