How do you one-up the world's best-selling helicopter, the Robinson R44? Simple. You put a turbine in it. But wait! … It wasn't that easy.
Talk of a "Robinson turbine" began swirling around the helicopter community clear back in 2001. But if you asked company CEO and founder Frank Robinson back then if the company was indeed working on such an animal, he would smile and get very elusive. Truth is, Robinson had been thinking about a kerosene-powered helicopter for some time, but he wasn't happy with the engine choices available to power the design. Everything he looked at, including the Rolls-Royce 250-C20B, lightest of the offerings, was too heavy — and too expensive. Over the years, while the turbine project moved from front burner to back shelf to front burner, Robinson investigated many power-plant options, including diesels. But the diesel options were all too heavy and didn't offer enough advantages over the small turbines available.
So Robinson went to Rolls-Royce, asking it to design a "lighter, simpler, less expensive" turbine to power a slightly scaled-up R44. The result was the RR300, a new design with deep roots in the Allison/Rolls-Royce Model 250-C20 series turbine that has powered stalwarts such as Bell's JetRanger, Hughes/McDonnell-Douglas' MD-500 and others for decades. This new engine, certified by Rolls-Royce in early 2008, made possible a remarkable new helicopter that should be certified by the time you read this. It's called the Robinson R66 Turbine.
The new engine is indeed lighter — it weighs 201 pounds installed, less than half the weight of the IO-540 piston engine on the R44 Raven II sibling. The engine is also simpler, with a single-stage centrifugal compressor instead of the C20's more complex six-stage axial and one single-stage centrifugal compressor. It's rated at 300 shp maximum, 270 shp for five minutes and 224 shp continuous. Initially, the turbine will have a TBO of 2,000 hours — 200 hours less than the airframe's required overhaul time - but Rolls is determined to raise that as it gets field experience with the new design.
Engine bleed air is utilized for engine anti-ice and cabin heat, which, as in all turbines, robs power when it's selected. The performance charts reflect this degradation in performance, advising you to add 10 degrees C to the outside temperature numbers when engine anti-ice is on, or 20 degrees C if cabin heat is on. But with bleed air off, the ability of this ship to hover out of ground effect is impressive: more than 12,000 feet at maximum gross weight.
That "lighter, simpler, less expensive" design philosophy is obviously a steadfast core belief at Robinson helicopter. Kurt Robinson, who took over the reins as CEO and president of the company this summer when his 80-year-old father retired, told me proudly, "We build Fords and Chevys here." The message was that the company's light, simple products perform well and inexpensively without flash and complication. This new turbine helicopter comes to market at a price point that will ensure its success: $790,000. To put that into perspective, when Bell abandoned its entry-level 206B-3 JetRanger III production in 2008, it was priced at around $1.3 million, reasonably equipped. That leaves only two other competitors for the R66: The Sikorsky S-333 at about $900,000, average equipped, and the Enstrom 480B, which sells for about $1.05 million to $1.1 million.
Simple Is as Simple Does
Preflighting the new design is simple and straightforward. The usual scrutiny of blades, skids, cowlings and general airworthiness items is unremarkable. At first glance, the only things to differentiate the R66 from the R44 are the turbine engine's intakes at the base of the main rotor-mast fairing and the cooling screens located aft, above the engine compartment. But the main rotor mast is 8 inches higher, and the new machine is 7½ inches wider than an R44.
Another difference is the type of main rotor blades. In field use, Robinson found that its stainless-steel main rotor blades were too easily damaged, so it has gone back to aluminum blades for the entire fleet from R22 to the R66 Turbine; a set of aluminum main rotor blades is about a pound lighter than the stainless, thus payload is improved slightly, and autorotation characteristics are unchanged. The main rotor disc area of the R66 is the same as in an R44, though the chord is 1½ inches wider. The tail rotor blades also have a slightly wider chord and are 2 inches longer than an R44's blades.
There is an access door on the left side of the aircraft that offers a great view of the lower mast area. When opened, a microswitch automatically turns on small LED lights that illuminate the hydraulic reservoir, main rotor gearbox and other essential inner workings that should be checked before flight. Nice touch. On the right side of the aircraft, a large access door opens to reveal a large portion of the engine compartment. There is also an access door on the left side of the helicopter's upper deck that covers the fuel filler cap. Contact switches on each of these doors and the baggage door annunciate to warn the pilot if any are left open.
As in most new aircraft these days, all aircraft lights, including position, beacon strobe and instrument panel, are LED types, which draw very little power and are lighter and longer lasting. The nose-mounted landing lights are HID, or high intensity discharge. This should remove any objection to running all the lights, including landing lights, all the time for extra visibility.
The new baggage area is accessed through a large, top-hinged door, located slightly below and aft of the right rear cabin door, and opens wide to a generous baggage area. Though I was assured golf clubs would fit (I didn't bring mine for this evaluation), they must be removed from the bag. There's a 300-pound limit on the compartment, and since it is just aft of the rear seats, aft CG shouldn't be a big issue.
The cabin doors are the same light, simple doors found on all other Robinson products, with small, stay-open gas struts for ease of entry and exit. Inside, there is seating for five, although the "fifth seat" is a rather narrow rear middle seat, slightly elevated and forward of the two outside seats. This allows three-abreast seating without having the passengers' shoulders jammed together, though headroom is a bit tight. I sat in the seat for a few moments, and my head (I'm about 5 feet 10 inches) was right in the headliner. For ride-hopping or short flights, that would be acceptable, but this seat is not for long trips. Kurt Robinson admits that the R66 is "an honest four-place," saying, "It's just like in your car; you can go across town with all seats filled, but you might not want to go all the way across the state of Texas that way."
The seats of this helicopter are deceivingly simple; they appear to be small cushions with a light, flip-up hinge, but the seat structure is certified for 20 G loads. They are also built for a maximum 1,500-pound spinal compression load. This was admittedly one of the hardest things to get right during certification, and Robinson admits it took several attempts to finally show compliance with FAR 27 requirements.
Under-seat storage is also reduced from previous Robinsons. Now, there is a fiberglass housing attached to the aluminum seat bottom that provides additional vertical crush capability in an accident. The new housing also restricts the amount of cargo that can be put in the compartment below the seat. There's a new placard inside the compartment showing the maximum height to which cargo can be loaded; this is designed to keep operators from overfilling the compartment and reducing the seat's crashworthiness. But the new baggage area compensates for these new restrictions because it accommodates so much cargo.