Unless you have stood next to a Bell/Boeing V-22 Osprey tiltrotor–and you won’t be able to at Le Bourget this week because it’s not here–it is difficult to fully comprehend what an impressive piece of engineering it is and what a struggle of wills it must have taken to bring it to this stage. It has taken a monumental effort to conceive, resource, design, build and, frankly, at times bludgeon such a revolutionary aircraft through to the point where the decision whether or not to enter full-rate production is a matter of weeks away.

The V-22 isn’t here because the U.S. Marine Corps’ second stab at the tiltrotor’s operational evaluation (opeval) is reaching a climax. Since April, members of VMX-22 test and evaluation squadron have been flying eight MV-22s on practice missions in the desert surrounding Nellis Air Force Base in Nevada.

Coast-to-Coast Maneuvers

Each two-airplane section has flown long-range practice raids, airborne assaults, casualty evacuations, air-to-air refueling and external lifts–in daylight and, since late April, with night-vision goggles. To reinforce its crucial self-deployment capability, one flew from coast to coast, refueling from Marine KC-130 tankers en route.

Meanwhile, a further detachment from the New River, North Carolina-based squadron has tackled high-altitude and colder weather conditions near Bridgeport, California. On completion, the unit continued the program on the East Coast and aboard U.S. Navy amphibious ships. [Separately, an Osprey completed icing tests in the area surrounding Halifax, Nova Scotia.]

As well as evaluating the MV-22’s airborne performance, Marines have been poring over the aircraft’s recommended maintenance procedures and techniques, looking for last-minute tweaks that can be made before the design of the final production model is frozen.

Opeval is a major hurdle for any aircraft program but the Osprey has overcome a peculiarly troubled, decades-long gestation. (The U.S. Department of defense established the V-22 program in December 1981 and first deliveries to the Marine Corps were expected in 1992.) The program has endured a series of engineering problems, several politically induced delays, two fatal crashes and even a records-falsification scandal. On at least two occasions, the program came to within a hair’s breadth of cancellation. In 2000 it passed opeval and was deemed ready to enter service, but the two subsequent accidents raised serious questions about the aircraft’s design, maintainability and utility and led to a broad reassessment of the program.

During this test process, the squadron has tried to settle any lingering doubts that might remain about the aircraft, such as its ability to operate, as Marines generally do, in harsh terrain and tough climates. “There are [still] questions in Congress’ mind about this capability,” acknowledged VMX-22 commanding officer Col. Glenn Walters. He uses photographs of a recent training exercise, showing Ospreys landing at a dusty zone in near-zero visibility, to brush off criticism that fine sand might clog the engines or disorient the aircrew.

Easy In-and-Out

“The aerodynamics of this aircraft let you take advantage of certain factors,” he said. Getting in and out of a zone is easier because, unlike helicopters, the Osprey does not need to flare or nose down during landings and takeoffs. Instead, its twin nacelles are angled to provide the lift needed and keep the debris largely out of the pilots’ vision.

VMX-22 stopped flying in January to save wear on their prop-rotor gearboxes, where flaking chrome had triggered a series of chip warnings. Program engineers attributed the problem to faulty bearings and it was “addressed and solved,” according to a spokesman.

With a clean bill of health once more, other tests are under way. The U.S. Air Force Special Operations Command is evaluating a CV-22 special ops version in night/foul weather flying, nap-of-the-earth, and search-and-rescue at Edwards Air Force Base in California. A new training squadron has been activated at Kirkland AFB, New Mexico, prior to accepting the first of six CV-22s by March 2006. The U.S. Navy, meanwhile, is eyeing a version for its own search-and-rescue requirements, and overseas air arms, including the British Navy, have evaluated it with feedback from exchange pilots.

By July, activity will subside as the written trials report is forwarded to the Department of Defense and Congress. Finally, Pentagon acquisition officials will make the decision whether or not to allow the Marine Corps to buy 360 of the tiltrotors to replace its medium-lift helicopters. Bell/ Boeing anticipates a full-rate production decision in the fall, possibly as early as September.

Then, all those who have kept faith in this remarkable aircraft will know whether it really has a future. If it does, the odds on it missing the Paris 2007 show will be very short indeed.