Powerful growth model of prolific turbine spins off latest engine technology
Five years ago, when delivered the first RR300 to Robinson Helicopters, many believed the advent of the new-generation engine marked the beginning of the end for its predecessor, the ubiquitous M250.
Yet, partially thanks to the RR300, the fortunes of the M250 are improving markedly. A new, high-powered variant of the family, the M250-C47E, which leverages advances made for the RR300, is being unveiled at this week's Heli-Expo show in Las Vegas. Originally introduced by Allison in the early 1960s, the turboshaft is gaining a new lease on life as Rolls marks the delivery of the 31,000th unit.
“In terms of production, we've seen a 20% year-on-year increase for both the RR300 and M250 from 2011, and 2013 is sold out,” says Greg Fedele, Rolls-Royce senior vice president for helicopters. “We've seen an upturn in the vertical-lift market, specifically the Bell 407 and Robinson R66, and we're ramping up production.”
To date, more than 500 RR300s have been delivered to Robinson's Torrance, Calif., production facility, says Fedele who adds that long-anticipated additional applications may finally be realized. An agreement to use the powerplant for a proposed reengined Bell 47 program has been signed with Scott's-Bell 47, and “we are in discussions with another airframer on another new application for that engine,” he adds.
The memorandum of understanding with Scott's-Bell 47 (SB47), a Minnesota-based upgrade and modification specialist, covers the potential development of a new-build version powered by the RR300 turboshaft. Since acquiring the type certificate from Bell in 2010, SB47 has had ambitions to put an updated variant of the venerable helicopter back into production. SB47 is a sister company of Scott's Helicopter Services, the world's largest operator of the Bell 47, as well as Texas Helicopter, an-approved parts supplier and supplemental type certificate (STC) holder for the Model 47. The study agreement with SB47 follows the long-standing development of an STC to reengine the Bell 47 with the Rolls M250 turbine.
The launch of the -C47E follows “requests for more hot-and-high performance and increased power across the envelope,” Fedele says. “It's a new series of engine that incorporates the RR300-derived Value Improvement Package (VIP) kit and a dual-channel, full-authority digital engine control (Fadec). We're increasing the power rating to 700 shp (an 8% increase over the current series), and we can increase this even more if an airframer asks.”
As a result, the -C47E will have improved hot-high performance, “as well as lower direct-operating costs and lower fuel burn,” says Fedele. The enhanced engine, which is configured with a similar mounting arrangement to the -C47B/M models, is expected to show a 5% improvement in hot-and-high power as well as a 2% reduction in specific fuel consumption. The first test units will begin flying this year, with the production certificate anticipated early in 2014.
The VIP kit takes the compressor aerodynamics and technology developed for the RR300 and incorporates an enhanced diffuser, new first-stage impeller and nozzle. The VIP kit was in limited service by early 2012 and is offered for the C47B, powering the Bell 407, and C47M, powering the MD600, both rated at 650 shp. With the kit, they provide a 5% surge-margin improvement in hot-and-high conditions
Rolls says it has secured a launch customer for the -C47E on “one new and two current aircraft applications” but declines to identify these before the start of Heli-Expo. The company adds that other military customers “have expressed strong interest, with a demonstrator engine already delivered for installation in a flight-test aircraft.”
The M250 powers the Schweizer 330-basedRQ-8A/B Fire Scout vertical-takeoff unmanned air vehicle and, in its updated form, is slated for the follow-on Bell 407-based . Northrop will use the new engine in a risk-reduction demonstrator vehicle for the U.S. Navy's MQ-8C. Initial flights will take place later this year, says Fedele.
Rolls-Royce also plans to unveil an enhanced series of support plans for the RR300, the newest element of which will be introduced by the end of this month. The new plan builds on the current Total Care power-by-the-hour program under which R66 operators have two options: 1) spread the cost of scheduled maintenance over time, or 2) pay for a comprehensive maintenance package that includes unscheduled engine removals. The new plan will enable operators to pre-pay for a discounted package covering both scheduled maintenance and unscheduled removals. “They will be able to finance it now or pay it in cash and have that value built into the aircraft,” says Fedele. “[Rolls] is doing the analysis now on a similar plan for the M250.”