Monday, September 1, 2008
Robinson R44 Raven II Helicopter: Piston Chopper
With four seats, a 112-knot cruise and the lowest price in the class, Robinson’s R44 is perhaps the ultimate multitasker
|In case all you fixed-wing pilots hadn’t noticed, Frank Robinson’s success in the light helicopter market has been nothing short of spectacular. Robinson Helicopter Company (www.robinsonheli.com) has sold some 8,500 helicopters in the last three decades.|
Certainly, a major attraction of the R44 is the type’s operating economy. Part of that’s a function of the aircraft’s relative simplicity, but another major factor is the choice of powerplant. Robinson is one of only two helicopter manufacturers employing piston engines (the other is Schweizer). The Torrance-based company has opted for the tried and tested Lycoming IO-540 engine, normally rated for as much as 350 hp in other applications, but asked to deliver only 245 hp for five minutes and 205 hp maximum except take off (METO) power continuously on the R44. TBO is 2,200 hours for helicopters operated regularly and maintained to Robinson’s strict standards.
Back in the late ’80s, when I was training in a succession of R22s, instructor Tim Tucker used to joke that if I could learn to fly the little Robinson, I could probably handle any other civilian light helicopter on the market. The controls of the R22 and R44 are the most sensitive in the industry, one reason the types make excellent transition machines to something bigger, though many pilots may never feel the need to step up. Hydraulic boost eliminates cyclic stick shake and makes in-flight control a fingertip process. Standard equipment also includes an RPM governor that automatically controls engine rpm during normal operation.
|The Robinson R44 (above) hovers over Sea Launch Commander, the world's only ocean-based space launch company, in Long Beach, Calif. Below, the R44 flies an approach to a Holiday Inn rooftop in Torrance, Calif.|
The new R44 I flew was Frank Robinson’s personal aircraft, and as you might expect, it was outfitted with practically every option, the pop-out floats, a Garmin 500 GPS and TIS uplink. I spent two hours renewing acquaintances with the R44, relearning the delicate sensitivity necessary to hover and fly the machine.
Robinson test pilot and instructor Markus Turnow put up with my amateurish attempts at remembering how to hover, but it all started coming together as I remembered the secret of flying a “Robby”—understatement. If you don’t fly an R44 for a year, you’re almost guaranteed to over-control for the first half-hour or so, regardless of whether you’ve been flying any other helicopter.
The cyclic control, essentially the equivalent of the stick on an airplane, controls roll and pitch, and it responds to the gentlest inputs. For takeoffs and landings, the usual advice is to use your fingertips with your right arm balanced on your knee, keeping your eyes on the horizon rather than the ground below during landings—you’ll be surprised by how quickly the R44 becomes friendly.
Still, helicopters operate to very different parameters than fixed-wing airplanes. The overhead rotor serves as the equivalent of a wing, and maintaining rotor speed is critical. Losing rotor speed is somewhat analogous to stalling an aircraft wing.
For that reason, helicopters must fly in strict compliance with the height/velocity diagram, sometimes better known as the “dead man’s curve.” In order to operate the aircraft safely, you need to maintain either a minimum altitude, a minimum airspeed or a combination of both. In other words, you must maintain a height/velocity profile outside the shaded area of the curve.