The Next Generation: Satisfying the Next Operator

By James T. McKenna | August 1, 2008

Airframe makers are delving into what customers and operators want in their next generation of aircraft.

Airframe makers are busy trying to decipher what commercial operators want in their next generation of rotorcraft and refine their development efforts to ensure they are in a position in a decade or so to satisfy them.

Their efforts are being governed by demands, mainly from oil and gas companies, for greater degrees of safety and flight-monitoring capabilities, the latter for both enhancing pilot performance and for improving the reliability and reducing the operating cost of aircraft and their key components.


They are also driven by changes in the marketplace, particularly in the ongoing development of "secondary" emergency medical service markets in which the helicopter becomes the environment for supporting — and in some cases performing — highly specialized medical treatments rather than only a means of moving trauma patients from accident scenes.

Hanging over all the debates about the next generation of civil aircraft are the twin challenges of making rotorcraft safer and more environmentally friendly.

Manufacturers continue to wrestle with the question of how much operators are willing to pay for speed capability beyond the traditional range of about 150 kt for conventional helicopters. Its answer will determine the success of Bell Helicopter and AgustaWestland’s long-delayed BA609 and Sikorsky Aircraft’s pursuit of its X2 technology.

Hanging over all the debates about the next generation of civil aircraft are the twin challenges of making rotorcraft safer and more environmentally friendly.

The "point man" in the latest round of aircraft development is Bell Helicopter’s Model 429 light twin. The latest in a string of efforts by that manufacturer to launch an effective competitor to Eurocopter’s family of helicopters, the 429 has been newly vetted by Bell leadership, prodded by the company’s relatively new head President and CEO Dick Millman.

"Mr. Millman has inserted a very strict and rigorous ‘gate’ process for that we have to go through" in advocating launch or continuation of an aircraft program, said Mike Blake, Bell’s executive vice president of customer solutions. That process requires proponents to "really have a solid story on where the markets are, where the customers are, what the attributes are" that are needed to satisfy them.

Most importantly in that process, Blake said, is this question: "Can this program be executed to fill all the promises that are made not only to the customers but to the Textron shareholders as well." Textron is Bell’s parent company and Millman has convinced its executives to invest in expanding Bell’s production capacity, mainly for military products.

The 429 program has encountered some problems. Program officials spent March, April and May resolving a main-rotor instability problem with the aircraft’s prototypes.

That problem first appeared on the No. 3 429 prototype, which is the first pre-production aircraft. But Bell’s 429 program director, Neil Marshall, said subsequent testing demonstrated the problem was present on all the prototypes.

Bell engineers have redesigned the 429’s main rotor to increase its inertia and redistribute weight in the blades. The redesigned blades are in production, he said, and the second set should be finished this month and fitted to a prototype. All the prototypes will be fitted with the redesigned blades. The redesign adds 10-20 lb to the aircraft weight, depending on how each blade is balanced.

With that problem solved, "our biggest challenge is getting this thing completed and certified and starting deliveries." Bell’s goal for certification, which will be done by Transport Canada, is the end of this year or the first quarter of next year. It reports more than 330 orders for the aircraft.

Bell has accumulated more than 1,000 hr of flight test time on the three prototypes currently flying. The fourth prototype (and second pre-production aircraft) underwent a full-scale fuselage shake test in Fort Worth, Texas to correlate Bell’s analytical models — finite-element models and dynamic analysis — with the actual airframe as built, "which is something we’ve not done during the development phase of a program previously, but we felt there was a big advantage to do it," Marshall said. "The dynamics folks are going to learn a lot from doing that."

Those tests were completed in June and the aircraft has returned to Bell’s facility in Mirabel, Quebec. It was slated to begin flight tests by the first week of this month.

The third pre-production aircraft is to be used for electromagnetic interference and compatibility testing of avionics and electrical systems starting next month.

Marshall said the program has completed power-assurance and power-available testing with the inlet barrier filters that will be part of the 429’s initial certification configuration. (Bell later plans certification of a version with no filters.) It also has completed testing on inlet distortion, engine restarts, snow ingestion and hover and climb performance, among other tests.

Cold-weather testing included aircraft starts down to -40 C with a small battery. "That was a good milestone for us on the aircraft," Marshall said. "That’s where we wanted to get to with the small battery" so operators don’t have to incur the weight penalty of carrying a large batter for cold-weather operations.

Bell had its final customer advisory council in December 2007. "We’ve had their input since late 2003, early 2004 and that really shaped how we designed this aircraft," he said. "Fortunately, it’s very much coming out where we wanted it to be in terms of performance."

According to Bell officials, the 429’s hover-out-of-ground-effect ceiling is proving to be 11,800 ft rather than the specified 9,300 ft at max gross weight and ISA conditions. Cruise speed at max gross weight at sea level and ISA conditions is reported to be "significantly higher" than the specified 142 kt.

Bell continues to work at being responsive to customers in refining the 429. Based on input from EMS operators in Europe and Asia, it plans to add a tail-rotor guard after initial certification to prevent people from walking into those spinning blades. It has incorporated large access panels in the aircraft nose and on the engine deck to ease maintenance, and designed the tail boom with a flat underside to simplify the installation of antennas.

Beyond the 429, Bell continues to pursue development of a new medium product. The manufacturer has been polling potential customers on the desired configurations and capabilities for that aircraft for more than a year; the concept reportedly has undergone major changes in that time, including an alteration of its name. Bell executives as recently as late 2007 referred to it as the New Medium Twin. The change may reflect a desire to drop a name adopted under the previous CEO Mike Redenbaugh, or Bell’s new strategy of pursuing families of helicopters derived from single type certificates.

Nonetheless, Blake at the Farnborough Air Show said the new medium product effort "is in the very early stages of study and analysis."

For its part, AgustaWestland is preparing to launch a new aircraft, currently dubbed the XX9.

Also at Farnborough, the British-Italian manufacturer’s CEO Guiseppe Orsi, explained to Rotor & Wing that he wants to launch this 4-5-ton aircraft by the end of the year. The XX9 would fill a gap in AW’s product line between the 3.5-ton A109S Grand and the 7-ton AW139 medium twin.

AW already is at work on developing concepts for the XX9 program, which likely would be unveiled officially at Heli-Expo 2009. A target market for the aircraft apparently is the EMS sector, particularly the growth segment of it that transports patients to and from highly specialized care centers.

"We see these secondary markets in EMS developing very quickly," said Roberto Garavaglia, AW’s marketing director.

While EMS once was an activity squeezed into existing helicopter designs, "now you have to take into account the EMS operator from the beginning," he said. "The EMS requirements are not a byproduct but a major part of the system."

He also noted that EMS operators are getting familiar with the Grand, "and you never want anything smaller."

Operators rarely ever want something slower, either, so Sikorsky continues its efforts to plumb the appetites of operators for speed through its X2 technology demonstration program. That program is working deliberately toward a first flight of its lone prototype. The mantra of Sikorsky’s new advanced programs manager, Jim Kagdis, is that the first flight is "within arm’s reach."

However, Sikorsky officials previously had told R&W the program’s plan called for about 10 hr of "bare-head" ground runs, without the coaxial main-rotor blades installed, followed by about 65 hr with those blades on. Then the aircraft would have to be run on the ground for about 10 hr with no changes to its flight-control or integrated-power system software before it could be cleared for the first flight.

The aircraft was first run with main rotor blades May 13 and by Farnborough had accumulated about 14 hr of run time, according to Kagdis.

He said Sikorsky plans to "put another dozen or so" on the aircraft before first flight, followed by "a couple dozen for Phase 1 flight tests" at the company’s rapid-prototyping center at Schweizer Aircraft in Horseheads, N.Y. Then the aircraft would be moved to Sikorsky’s flight test facility in West Palm Beach, Fla. for the next three phases of flight tests.

The tests in New York would take the X2 from hover to 40 kt forward speed. Those in Florida would progress from 40 kt to 120 kt, then to 180 kt, then to the program goal of cruising at 250 kt.

That speed goal is just one of four key performance parameters, he said. The others are low acoustics, low vibration levels in flight and low pilot workload.

The other high-speed civil effort, the Bell/Agusta Aerospace BA609 tilt-rotor, seems to be bogged down by funding disputes and doubts about its viability. AgustaWestland officials remain confident in public that the civil tilt-rotor will succeed in commercial markets, include EMS and search-and-rescue ones. At Farnborough last month, the BA609 display included a mockup of a SAR configuration for its cabin. Bell officials see the Sikorsky S-92 and very light jets eating into U.S. markets for the aircraft.

Having launched development of its new medium twin, the EC175, Eurocopter is turning its attention to pursuing the "green," so called not for its primer-colored fuselage, but by its fuel efficiency and environmental friendliness. "Customer demand for greener rotorcraft is driving a new phase of technology development," Marc Paganini, president and CEO of American Eurocopter told the American Helicopter Society International’s annual technical forum in Montréal last April. He said demand for greater fuel efficiency, lower exhaust and noise emissions and a lesser impact on the economy through the service life of an aircraft is motivating Eurocopter’s efforts, which are backed by funding from the European Union.

In addition, he said, "the demand for ‘airline’ levels of safety is driving a parallel focus on aircraft and mission safety."

With civil markets sustaining their growth despite global economic turmoil and the environment becoming a bigger factor in aircraft design and operations, airframers shortly will be forced to place their bets on where the future lies for commercial helicopter markets.

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