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This article was Originally Published on May 01, 2002 in Volume: 1  Issue: 2

Osprey Flight testing to Resume

Few aircraft in the history of aviation have been so praised by its pilots who fly them and yet so controversial as the Bell-Boeing V-22 Osprey.

By Bob leder

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Few aircraft in the history of aviation have been so praised by its pilots who fly them and yet so controversial as the Bell-Boeing V-22 Osprey. A totally revolutionary aircraft, the V-22 Osprey is the world's first production tiltrotor. The Osprey's outboard wing-mounted nacelles are capable of rotating from the vertical position for helicopter mode to the horizontal position for airplane mode. In helicopter mode, the V-22 is capable of taking off, hovering and landing much as any large multi-engine helicopter. In airplane mode, the V-22 can fly with the speed and range of a turboprop airplane. This extraordinary range of capabilities means the V-22 can fly twice as fast and at least twice as far as any helicopter in the world.

The V-22 fleet already has amassed in excess of 4,000 hours of flight time since the program's inception in the late 1980s. Extensive independent and internal program and technical reviews after two accidents in 2000 have brought about improvements in aircraft systems that will be validated when flight testing resumes in late April. A full range of operational testing conducted over the next two years will ensure that the V-22 is fully capable and reliable over the entire range of tactical and support missions, in every climate and condition, for which it was designed and developed. A recent NASA report endorsed tiltrotor technology, citing its potential for both military and civil missions. NASA's support reflects the strong positive interest the V-22 has generated among nearly every agency, public and private, and individual with a stake in aeronautics and aviation.

This is not new or experimental technology. Tiltrotors have been flying for 45 years, spanning three different generations of tiltrotor aircraft from the first tiltrotor - the XV-3, which first flew in 1956 - to the XV-15, which first flew in 1977 and is still flying today, to the MV-22, which made its first flight in 1989, and the Air Force model, the CV-22. There is even an unmanned tiltrotor - the Eagle Eye UAV - that has been flying successfully since 1994.

With more than 6,450 flight hours in all types, it is clear tiltrotors are reliable aircraft - revolutionary, to be sure, but reliable. More than 350 people have flown tiltrotor aircraft over the years, and all were impressed with what the technology brings to aviation.

An Increase in Lift Capability

The V-22 Osprey tiltrotor will provide a significant increase in medium vertical lift capability for the armed forces of the United States and its allies. It will provide twice the speed and range, and three times the payload, of the conventional helicopters used by the U.S. Marine Corps. For the U.S. Special Operations Forces (SOF), it will provide a capability that does not exist in their present forces, the ability to insert or extract SOF out to a 500-nautical mile radius of action during one period of darkness and in any weather. The U.S. Navy will get a multi-mission aircraft for long-range combat search and rescue, fleet logistics support and special warfare. Only the tiltrotor provides a vertical lift capability with the speed and range to meet these multi-service, multi-mission requirements. Its unique ability to self-deploy worldwide will allow for a more effective and rapid response to the crises of the 21st century.

The potential of tiltrotor technology to significantly increase service combat effectiveness is not limited to the basic missions for which the airplane was designed. In fact, the Osprey will be a catalyst for a revolution in military affairs that will change the way all services deploy and operate vertical lift forces. It will support the concept of operations of widely dispersed, highly lethal long-range maneuver from land or sea. Additional mission applications such as Air Expeditionary Forces (AEF) support, Combat Search and Rescue (CSAR), Airborne Early Warning (AEW), Aerial Refueler and Medical Evacuation are emerging.

With both military and civil applications, tiltrotor technology, when combined with the worldwide navigation accuracy of GPS, will allow for safe and efficient air travel, to and from any spot on the earth's surface without the need for airport runways.

It allows more airport slots and hence, efficiency, for larger aircraft carrying more passengers. They can be fed by tiltrotors operating in and out of airports without using runway slots. Furthermore, it allows air transport to and from places that cannot accommodate an airport such as mountainous and dense urban areas, islands, etc.

Helicopters have been limited to air speeds of 150 knots, ranges of 400 nautical miles and altitudes of 10,000 feet. The tiltrotor expands the helicopter envelope to speeds of 300 knots, ranges of 1000 nautical miles and altitudes of 25,000 feet. It incorporates the efficiencies of the turboprop airplane with the versatility of a helicopter - in one aircraft that needs no runway.

Fifth Years of R&D Recalled

Bell Helicopter Textron Inc., and the Boeing Co. moved tiltrotor technology into production after nearly 50 years of research and development. The Bell Boeing Tiltrotor Team formed in 1982 to begin the design of a new aircraft that would provide new capabilities to meet realistic challenges of the 21st Century. The V-22 Osprey is the aircraft that has resulted from the contributions made by thousands of Bell, Boeing and supplier employees. Tiltrotor technology moves the world into the next millennium and will change the way the world flies.

Four Engineering and Manufacturing Development (EMD) Ospreys, aircraft numbers 7-1, completed developmental envelope expansion in the summer of 1998. They achieved such milestones as a 3.9 g load factor at 260 knots, 60,500 pounds maximum takeoff gross weight, 25,000 feet in altitude, a maximum speed of 342 knots, night flights using night-vision goggles and external loads of 10,000 pounds at 230 knots. Aircraft 9 and 10 completed the last phase of operational testing (OT-IID) prior to operations evaluation (OPEVAL). Pilots with the test team, along with the Multi-service Operational Test Team (MOTT) have flown more than 950 hours on the EMD aircraft. V-22s have flown more than 2,100 hours since first flight in March 1989. Initial sea trials were flown aboard the USS Wasp (LHD-1) in December 1990 using two full scale development V-22 aircraft. Sea Trials with the production representative (EMD) V-22 began in January 1999 aboard the USS Saipan (LHA-2).

The V-22 is operationally effective and operationally suitable. On Oct. 31, 2000, on board the USS Bataan (LHD-5), The Navy's Commander, Operational Test and Evaluation Force (COMOPTEVFOR) declared the V-22 operationally effective and suitable. Since that time maintainability and reliability improvements have been incorporated in production aircraft based on the recommendations during the test evaluation and OPEVAL. The V-22 was documented as the best prepared aircraft in naval aviation history before entering the OPEVAL phase of testing.

The CV-22 is the first variant of the U.S. Marine Corps MV-22. It's unique features include additional fuel tanks in the wing for extended range of more than twice that of the MV-22; a multi-mode radar for terrain following/terrain avoidance flight, more sensors, radar jamming equipment and a suite of integrated radio frequency countermeasures. It will also have an installed refueling probe; a third seat in the cockpit for the Air Force special operations flight engineer and two and a half times more flare and chaff rounds. The CV-22 will replace the MH-53J helicopter and augment the MC-130 fleet in Air Force Special Operations Command, Hurlburt Field, FL. The V-22 Osprey's multi-mission capabilities will serve both the Air Force and Marine Corps.

A New Level of Efficiency

Tiltrotor technology is the most outstanding aviation technology development in the past 50 years - especially from the users' viewpoint, both military and civil. Its future has no boundary.  The V-22 was designed from the ground up to be a modern self-deployable, shipboard compatible, rugged combat rotorcraft. It has twice the speed, three times the range and much more payload than the helicopters it is replacing. It has been designed to combat the projected threats of the small arms, IR and radar directed missiles. It has a modern cockpit with state-of-the-art navigation, communication, passive defense, and threat warning systems.

Its diagnostic and health monitoring systems will reduce its maintenance to a fraction of that required in today's helicopters. Fail-safe and crashworthy features have been incorporated to a greater extent than with any fielded VTOL aircraft for both the cockpit crew and the troops in back.

It is, the team believes, the finest combat assault and special operations rotorcraft ever built. Unfortunately, many have rushed to judgment without waiting for fact, or ignoring those that have been presented to them. Some have offered pure fantasy and some just poorly informed. It is important to discuss several of these myths and present the facts, as they are known regarding the V-22:

Issue: Operational Test Waivers: major deficiencies were waived during the test program.

The V-22 program management requested and received 22 operational test waivers prior to beginning OPEVAL. This is the lowest number of waivers of any aircraft in recent history. By comparison, the waivers for two recently acquired aircraft were 59 and 72 waivers respectively. None of the waivers for the V-22 were safety related and each had a detailed plan in place to address the resolution/fix for the waived item.

Issue: It has been said that the V-22 is unstable and a difficult aircraft to fly. That it requires extraordinary skills to keep the aircraft safely airborne.

Pilots who have flown a tiltrotor will tell you that it is one of the easiest aircraft to fly that they have ever flown. How can that be?  Like every good airplane, it handles predictably, and smoothly, and lives up to what those who have flown it have said about it. Most are comfortable after only a few minutes of operation. I have seen non-pilots take an hour of instruction in the simulator, then land safely on simulated oil platforms at sea.

Issue:  Deleted Flight Testing.

The "deleted test points" that have been the subject of press reports represent a fraction of the total test events and "test points" collected during the Engineering Manufacturing Development (EMD) phase. Test events are scheduled for each flight, each one containing a specified number of test points to be collected during the conduct of that event. The purpose is to identify a safe flight envelope for the aircraft. The developmental test for the V-22 was comprised of approximately 2,200 test events of which 1,941 where actually flown.  This equates to 90 percent of the data test points and those that were not flown were approved during modifications to the Test and Evaluation Master Plan (TEMP). The objective was to identify and document a safe and conservative flight envelope. That's what was accomplished. This flight envelope is the normal flight operations performance window such as speed, angle of bank, rate of descent, etc. Flying the aircraft inside this envelope ensures the safe operation of the aircraft.

Issue: The V-22 cannot autorotate if it loses both of its engines.

Again, not true. Autorotations are aerodynamic procedures that allow rotorcraft to land without benefit of engine power. The typical reasons for autorotations are loss of tail rotor or total engine failure. The V-22 is not a helicopter. It does not autorotate like a helicopter. It is a tiltrotor, and thus autorotates like a tiltrotor. Rates of descent and touchdown speeds are different for each helicopter based on weight and other characteristics of the aircraft.  There are approved procedures in the NATOPS Manual for emergency landings when the nacelles are in the helicopter mode or the airplane mode.

Issue: The V-22 cannot do external lift operations and ground personnel cannot work under it while in hover because of its high downwash.

Well, the first statement is absolutely untrue, of course. The V-22 has a different downwash pattern than the two aircraft it is replacing for the Marine Corps and the helicopter it replaces in the Air Force Special Forces. This required a modification to the procedures for approaching and working under the aircraft - changes that have been implemented and work. The V-22 has demonstrated external sling load operations up to 11,700 pounds (1,700 lbs above the threshold requirement) over 50 miles with no difficulty.

Issue:  The V-22 is susceptible to Vortex Ring State

Every rotorcraft is susceptible to Vortex Ring State (VRS). It can occur at very low forward airspeed and very high rates of descent (less than 40 knots and greater than 800 feet per minute rate of descent). Flight restrictions prohibit operations in this regime for the V-22 and all rotorcraft. Based on test data, current restrictions are very conservative and provide a very large margin for safety. These "restrictions" are part of the normal flight envelope as developed in the initial flight test. Follow-on High Rate of Descent (HROD) testing is approximately 40 percent complete and is expected to conclude during CY 02.

Issue: The V-22 cannot operate in icing conditions.

The V-22 has been successfully tested in artificial icing conditions behind a KC-135 tanker spray rig in airplane mode and behind a CH-47 helicopter icing spray rig in helicopter mode. The weather became too warm to continue the test once. Natural testing is planned for this coming winter.

Issue: The V-22 Osprey is unable to fulfill Marine Corps requirements.

The aircraft can fly faster further, and with a greater payload than the requirements laid out in the Operational Requirements Document (ORD). The aircraft can and has carried 24 combat loaded Marines. Production representative Osprey aircraft carried an external load, which was 1700 lbs more than the ORD requirement. The Osprey also demonstrated the ability to self-deploy 2100 nm, four hours faster than the ORD requirement. The COMOPTEVFOR report cited 11 enhancing characteristics of the V-22, all of which are unattainable using helicopter technology. The director of operational test and evaluation stated in the beyond low rate initial production report, "In the planning and execution of missions, these three improved characteristics of range, speed, and payload can be interchanged and utilized in countless ways. Together they provide a major step ahead in tactical flexibility." The capability to self-deploy will provide the tactical commander flexibility in combat never before experienced." This is a tough airplane - nothing fragile about it - designed to be survivable in combat.

Issue: The V-22 is unaffordable and there are cheaper alternatives.

As far as "cheaper alternatives," 17 separate Cost and Operational Effectiveness Analyses (COEAs), Analyses of Alternatives (AoAs) and studies indicated that no helicopter, or mix of helicopters, could meet either the Marine Corps' Operational Maneuver from the Sea (OMFTS) mission or the Special Operations Forces (SOF) mission. They all said that the V-22 was the most cost effective solution. I believe the so-called alternatives also risk more lives of marines, special operation forces and the people they are to protect or rescue. They simply cannot do the mission. Why would anyone even suggest that they continue to do this mission with the limitations of yesterday's helicopter technology? V-22 is the most cost-effective solution.

In 17 separate COEA studies conducted by the U.S. government, the V-22 came out the number-one solution. Tiltrotor technology has not been the cause of either of the mishaps last year (April or December.)  Any loss of life is a tragedy in peacetime. However, history tells us that every new program has gone through pain. Over time we learn about the aircraft and how to utilize it.  In 2001, two separate independent investigative bodies, the Secretary of Defense's Blue Ribbon Panel (independent review panel) and the National Aeronautics and Space Administration (NASA) completed exhaustive studies into tiltrotor technology. Both organizations, comprised of the world's leading aerospace engineers, declared tiltrotor technology to be sound. The team believes in this technology. It will be good for the nation in civilian roles as well as the military.

Robert R. Leder is communications director for the V-22 Joint Program Office at NAS Patuxent River, MD.

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