Heli-Expo 2011: Uniflight Developing RR500 STC for Bell 206
Uniflight (Booth No. 2654) is developing a supplemental type certificate (STC) to install the 475-shp Rolls-Royce RR500 in the Bell 206. The $599,000 (2011 dollars, less engine core credit) STC includes the RR500 engine, new engine cowling and exhaust, Donaldson inlet-barrier filter and diffuser-vent filter and a Sagem eight-inch multifunction display for engine instruments. Uniflight CEO Joseph Hawke said the company hopes to have the STC certified in early 2013, shortly after Rolls-Royce receives the type certificate approval on the engine. Hawke sees an eventual market of up to 30 conversions annually, with initial orders likely coming from Bell 206L LongRanger operators, “who are still thirsty for additional power.” He said that replacing the stock RR250-C20B engine with the RR500 would reduce direct operating costs of the helicopter by an estimated $24 per hour, thanks mainly to reduced maintenance costs and longer overhaul intervals. The time between overhauls (TBO) on the RR500 increases to 2,000 hours for the hot section and first and second turbine wheels and to 4,000 hours for the power turbine and compressor. This compares to RR250-C20R’s TBO of 1,750 hours for the hot section and first and second turbine wheels and 3,500 hours for the power turbine and compressor. The life of the single-stage titanium impeller is measured in cycles and the limit for it has been set at 15,000.
Uniflight has hired Frank Shallene, a retired Bell program manager and propulsion engineer, as an FAA designated engineering representative, to develop the STC. Shallene said the new engine would give the 206 significantly improved performance. “The climb rate will be quite a bit better. Maximum payload will increase by 400 to 450 pounds. High/hot performance is going to be a stemwinder.” Christopher Fultz, Rolls-Royce RR500 program director, said the new engine can provide more than maximum continuous power from sea level through 20,000 feet within current transmission limits at “pretty significant temperatures.” Rolls-Royce plans to accelerate its testing program for the engine. To date, only one engine has been tested. It was run for 20 hours before inspection tear down. A second engine is being built and readied for automated endurance testing, scheduled to begin in the next few weeks. The initial engine test was absent of anomalies, and Rolls-Royce engineers plan to monitor the performance of the RR500’s new gearbox and lubrication system, among other variables, in the accelerated and automated tests. Fultz said certification testing should begin in June 2012 and take approximately seven months. He added that Rolls-Royce is working “to try and improve fuel consumption” of the engine, estimated at slightly more than 27 gph. However, “It is a bigger engine and it has more power, so it takes a little more fuel.” Hawke said that fuel consumption would not be a big factor in a prospective customer’s decision to upgrade. The majority of savings is related to the longer TBO and lower maintenance costs of the engine, he said. Uniflight plans to distribute the STC through authorized dealers and their affiliates and already has signed dealers in Canada (Skyline Helicopter Technologies) and Australia/New Zealand (HeliCenter). Both are Bell authorized service centers. The STC in much of the rest of the world will be sold through Bell independent representatives. “At this point we have 80 to 90 percent of the world covered,” Hawke said.