You might say that Osprey pilots are neither fish nor fowl.
- By John Croft
- Air & Space magazine, September 2007
(Page 3 of 5)
A typical flight begins with the ritual walkaround inspection and engine start, a highly automated process that takes about 10 minutes for both engines, says Tom Macdonald, senior Boeing test pilot for the V-22. Takeoff can be made vertically by keeping the two wing-mounted nacelles (each of which contains an engine, two gearboxes, and a three-blade, 38-foot-diameter propeller rotor on top) at the 90-degree angle (vertical), or from a rolling start by "beeping" the nacelle angle toward the horizontal using a spring-loaded rate-control thumb switch on the thrust lever. On the ground, nacelles can be pitched backward to 95 degrees for backing up—like a car in reverse—or tilted forward as far as 45 degrees for taxiing. To take off like a helicopter, Macdonald says the pilot pushes the thrust control lever forward "and the aircraft lifts straight up."
The transition between helicopter controls (tilting the rotor disks in various directions to bank, climb, dive, or yaw) and airplane inputs (moving flaperons on the wing and elevators and rudders on the tail) is managed by the triple-redundant flight computers. Macdonald says the process is "effortless" except for the large amount of pitch trim required to maintain level flight during transition from helicopter to airplane mode. The pilot adjusts the trim with a manual control in the cockpit. Once the transition is complete, the Osprey cruises at speeds near 275 mph.
To land, Macdonald explains, the pilot pulls back on the thrust lever within a mile or two of the runway. Once the Osprey slows to below 230 mph, the pilot uses the thumb switch to raise the nacelles, first to 60 degrees for the 125-mph downwind leg of the landing pattern, where the landing gear is lowered. Flaps in all modes are handled automatically by the flight computers.
On the final approach, pilots beep the nacelles toward the vertical position "three or four degrees at a time," says Macdonald, and land either like a helicopter (nacelles at 90 degrees) or like an airplane, with "run on" or "rolling" landings at speeds up to 115 mph and nacelle angles of 75 degrees or more. Macdonald says the same procedures work if one engine is dead, since both 6,150-horsepower engines share a common driveshaft.
For the Marines, a typical flight is a bit more complicated. "Learning to fly the V-22 is easy," says Smith. "Learning to fly it well is hard."
That's where training levels 200 through 600 come in.
Lieutenant Colonel Paul
Rock, commanding officer of VMM-263, says a typical day's work for his pilots might include a combination of formation flying, giving paratroopers a lift, ground-skimming night flights on night-vision goggles, aerial refueling, flying from the deck of a ship, hoisting vehicles and supplies, or "fast roping," in which Marines get to the ground by sliding down a rope from the Osprey's open rear deck. Rock previously flew CH-46s with HMM-263 but has been flying the Osprey since early operational testing trials in 1997. Rock, also an instructor pilot for advanced manuevers in VMM-263, says tiltrotor training differs from traditional CH-46 training in that pilots must become proficient in quicker ground operations, like approaching a landing zone, and flying longer-range missions at higher altitudes with aerial refueling, skills that are not an option for CH-46 pilots. As such, Rock says tiltrotor pilots, whether from a fixed-wing or rotary-wing background, take about the same time to complete training: Fixed-wing pilots tend to already have the higher-speed-approach skills down, as well as navigation and control abilities for long-range flights and aerial refueling, but need to become proficient in low-altitude troop and equipment-moving tasks, especially at night on night-vision goggles; helicopter pilots, on the other hand, are generally unfamiliar with the long-range, high-altitude operations.