New Rotorcraft

 - February 8, 2008, 5:51 AM

North American and European OEMs are proceeding with the development of new models for the booming civil helicopter market across a broad product spectrum, from light singles to medium twins. Almost all OEMs are reporting record or near-record deliveries, robust orders and significant backlogs. For example, a Bell 429 ordered today would not be delivered until 2014. The weakened U.S. dollar is also driving orders, with some OEMs, including Robinson, now reporting that most of their sales are outside the U.S. Certification is expected this year or early next year for several new models as well as significant upgrades of existing models.


AW119 Ke
The AW119 Ke received FAA certification in October (the helicopter received EASA certification a few months earlier, in June last year), and the first delivery is expected early this year. The Ke (which stands for Koala enhanced, an upgrade program announced at Heli-Expo last year) features an mtow of 6,283 pounds, 286 pounds heavier than the A119’s.

The Ke retains the A119’s engine–the Pratt & Whitney Canada PT6B-37A–but its main rotor blades are of improved aerodynamic design and make greater use of composites. Along with higher rotor rpm, this provides the additional lift capacity and better hot-and-high performance at high weights.


Bell 429
Bell continues to eye this year’s third quarter for certification approval of its $4.865 million light twin and says it has booked orders for more than 260. A new helicopter ordered today would not be delivered until 2014, although Bell is looking at ways to increase production rate short of licensing.

The third phase of the 429’s flight-test program began last month, when three production test aircraft were scheduled to join the two prototype aircraft. The current test program calls for this combined fleet to fly 1,400 to 1,500 hours before certification. By the middle of last month, 535 flight test hours had been logged. The current timetable calls for all test flying and certification reports to be completed by summer.

Flight testing late last year validated the 429’s service ceiling of 20,000 feet, and Bell announced that the 429’s design was “frozen” at the end of October. However, those tests will result in small changes to the production aircraft, including a more sculpted vertical fin to increase antitorque authority. A strake has also been added to the left side of the tailboom to improve handling qualities.

Bell is gearing up its 429 pilot training program, with instructors scheduled to begin training next month and customers in August. Frasca will be providing a Level 7 flight training device (FTD) for 429 training at Bell’s Customer Training Academy at Fort Worth’s Alliance Airport. The initial transition course will consist of 32 classroom hours, 6.5 hours in the FTD, and 5.5 hours flying the 429.

Concurrent with flight testing, Bell is continuing fatigue and life-cycle testing of 429 components, including the main rotor blades, actuators and dampeners. That testing will continue for several years after the helicopter achieves certification.


The BA609 Tiltrotor, the only civil heli- copter-airplane hybrid aircraft program, is progressing slowly. Two prototypes are flying–one at Bell’s facilities in Texas and one in Italy, near AgustaWestland’s Milan headquarters–and a third is slated to fly early this year.

Last year the joint venture officially applied for an FAA type certificate, starting the clock on the certification deadline (three years for Part 23, five years for Part 25). The FAA in October released a draft certification basis for the BA609. This suggests that the current certification target of late 2010/early 2011 might be more firm than previous ones.

The tiltrotor program has been plagued by delays since 2003. However, it has been gaining momentum since late 2006. As of last month, the two prototypes had flown a combined 275 hours. They had reached 310 knots in forward flight and 35 knots rearwards. AgustaWestland declined to supply more recent data for this report.

Last summer, AIN surveyed a number of potential customers and found interest to be waning. The EMS, offshore and executive operators AIN interviewed were cautious about operating a BA609, citing acquisition price, operating costs, cabin size or required takeoff and landing area as concerns. Bell/Agusta claims to have orders for 77 civil tiltrotors, down from the high of 80 it reported a few years ago, but up from the 70 recently reported. AgustaWestland CEO Giuseppe Orsi has said publicly that he does not expect a critical mass of demand for the 609 until at least 2025, some 29 years after the first customer ordered the aircraft.

The six- to nine-passenger BA609 is powered by two P&WC PT6-67As. Maximum range (without reserves) is 750 nm, while the maximum cruise speed is 275 knots. Mtow is 16,800 pounds.


Enstrom anticipates certification of the Chelton 60B EFIS system for its 480B single-turbine helicopter by this month. The system will become a TSO-approved–rather than STC–part of the helicopter. Enstrom sold fourteen 480Bs last year.


EC 175
The Eurocopter EC 175 program remains on schedule, and the first example of this medium twin will fly next year, according to the company. Developed under a joint venture with China-based Harbin Aircraft, the EC 175 will compete with the AgustaWestland AW139 in the six-metric-ton class. Design work is well under way with various Harbin partners. The critical design review took place on December 5 last year, “as planned,” program director Francis Combes told AIN. The EC 175 will be powered by two 2,000-shp Pratt & Whitney Canada PT6-67E turboshafts.

Certification is pegged for 2011. Harbin Aircraft is in charge of the airframe, main rotor, tail transmission, flight controls and fuel system. Eurocopter is responsible for the main gearbox, tail rotor, avionics, hydraulics and electrical system. The European company will also provide integration and flight testing. The joint venture will establish two production lines– one in Marignane, France, the other in Harbin.

The EC 175 (or Z15, under its Chinese designation) is designed for two-pilot IFR and single-pilot VFR operations when carrying up to 16 passengers. Preliminary specifications released in 2005 also included a 140- to 150-knot cruise speed and a 200-nm range. In December, Combes declined to confirm these figures. Harbin and Eurocopter are each investing E300 million ($440 million).

Hindustan Aeronautics

Indian-based manufacturer Hindustan Aeronautics Limited (HAL) is moving toward EASA certification of its Dhruv light twin. A tentative schedule calls for EASA certification early next year. Deliveries began in 2002 in India.
One example of the Indian helicopter has been flying since August with new turboshaft Turbomeca Ardiden 1H engines (Shakti, under its local designation). Replacing the TM333 from the same engine maker, the Shakti is designed to enhance the helicopter’s reliability and performance under hot-and-high conditions.
As of December last year, the Shakti-powered Dhruv had performed about 40 sorties. Turbomeca told AIN the flight-test program was progressing “as expected.” Cold-weather testing was due to start early this year. Almost simultaneously, a second Dhruv was to be fitted with Shakti engines.

According to chief test pilot Chandra Upadhyay, the Dhruv has been designed to meet JAR 29/FAR 29 requirements (European/U.S. requirements for helicopters heavier than 7,000 pounds). Last March, an EASA team visited HAL’s facilities in Bangalore to carry out an “initial airworthiness assessment.” The Dhruv is already certified for IFR operations in India, Chile and Israel, Chandra told AIN, and HAL is now pursuing equivalent approvals in Malaysia and Indonesia.

HAL claims the Dhruv is “at least 10 to 15 percent” less expensive than its competitors in the 12,000-pound-mtow class. Although the company is promoting the Dhruv for various roles such as air ambulance, parapublic missions, VIP and passenger transport, most of the approximately 80 sold so far have gone to the military.

The Dhruv, which can take off and land at altitudes as high as 20,000 feet, has been designed for operations in India’s mountains. “It has a wide center-of-gravity tolerance,” Chandra said. For an offshore mission, with 10 passengers and a crew of two, HAL asserts the Dhruv can fly 300 nm. Its best-range speed is close to 120 knots.


At press time Robinson was awaiting certification of the first Rolls-Royce RR300 turboshaft so it could begin certification flight testing of the R66 turbine single, a helicopter it announced last year. The helicopter seats five, has a luggage compartment large enough for golf clubs, and shares many of the design and control features of Robinson’s piston-powered four-seat R44, including a T-bar cyclic, two-blade main rotor and open cabin configuration.

Company founder Frank Robinson said he expected delivery of the first certified 300-shp RR300 engine by the end of last month. He said the price of the R66 would be between $400,000 and $1 million. A photo released last year by the Robinson Owners Association of an R66 flying testbed suggests that the new helicopter has a somewhat longer and wider fuselage, longer tailboom and taller main rotor mast than the R44. Frank Robinson said that the flying test bed is similar in appearance to the production aircraft. He said the goal was to certify the R66 this year but acknowledged that achieving that objective was “highly unlikely.” Robinson said that the company would not publicly unveil the R66 until it is certified. He said the helicopter’s design was not frozen. “We’re still improving some things and fooling around with others,” he told AIN last month.


Schweizer 434
The Saudi Ministry of Interior, having signed an order for nine, is the launch customer for this more powerful derivative of the single-turbine 333 trainer. At press time, a Sikorsky spokeswoman was unable to provide more detailed performance and price information on the 434.

The S-76D program, an update of Sikorsky’s venerable civil twin-turbine, completed critical design review in November and now proceeds to fabrication and test phases with an eye to certification next year. The -D will feature new composite main rotor blades, a quiet tail rotor, rotorcraft icing protection (for flight into known icing conditions), a health and usage monitoring system and a glass cockpit, including integrated digital maps.

The latest edition of the S-76 will be powered by all-new Pratt & Whitney Canada fadec PW210S engines (1,000 shp each, estimated). The four development engines have accumulated 550 hours and continue testing at P&WC Montreal. The new engine/composite main rotor combination will give the S-76D up to 1,000 pounds of additional lifting capacity in hot-and-high conditions and boost range by 50 miles over the S-76C+.

Testing is proceeding at other component manufacturers as well. Thales is conducting avionics and flight control integration testing of hardware and software and is scheduled to deliver components for the prototype aircraft early this year. The Thales TopDeck system will be integrated directly with the flight management system to allow dynamic construction of flight plans and easy access to other information, including Jeppesen charts that can be loaded onto the system via flash memory cards. The system features four 8- by 10-inch LCD displays (one primary flight display and one multifunction display for each pilot position) and are NVG compatible.

Eagle Aviation Technologies has produced components for the first engine inlet door and plenum scroll assembly. Eagle will fabricate the engine inlet assemblies for the production aircraft. Hexcel Structures will deliver main rotor blade components for the start of fatigue testing. The blade spar has been fabricated and is undergoing fatigue testing. Blade skins and core elements also are being fabricated. The main rotor blades will be installed on an S-76 test aircraft early this year and will undergo validation flight testing. EDO Fiber has started fabricating flexbeam and skin components. The flexbeam to be used for the fatigue test has undergone conformity inspection and is being prepared for test facility installation. The flexbeam is one of several new tail-rotor components that is part of a new design aimed at producing lower noise levels as part of the Quiet Aircraft Technology Demonstration (QATD) requirement.

The first two S-76D fuselage assemblies have been delivered from Aero Vodochody in the Czech Republic to Sikorsky’s Keystone Helicopter subsidiary in Pennsylvania. These fuselage assemblies are being prepared for the modifications that will transition the aircraft from the current S-76C++ helicopter configuration to the S-76D.

X2 Technology Demonstrator
Sikorsky had aimed to fly its X2 coaxial compound demonstrator before the end of last year, but that did not happen. A company spokeswoman said Sikorsky would make an announcement about the project at this month’s Heli-Expo.

Late last year the X2 was undergoing a second round of ground tests at Sikorsky’s Schweizer “Hawkworks” subsidiary in Elmira, N.Y.

Sikorsky announced the X2 in 2005. The helicopter features fly-by-wire flight controls and combines components from existing Sikorsky aircraft, including the
S-76, Black Hawk and CH-53, and other manufacturers’ aircraft. All of the components were scrutinized for their ability to enhance the X2’s mission of high forward speed and low vibration.

Power for the 6,500-pound X2 comes from a single LHTEC (Light Helicopter Turbine Engine Company) T800 turboshaft engine rated at up to 1,680 shp. The T800 drives the twin four-blade Eagle Aviation contra-rotating main rotors and the Aero Composites six-blade pusher propeller, or auxiliary propulsion system, mounted at the end of the tailboom.

Urban Aeronautics

Israel-based Urban Aeronautics is developing the X-Hawk, an unconventional rotorcraft that features two shrouded main rotors in tandem configuration. The company is simultaneously working on a full-size, 11-passenger version and scaled-down unmanned vehicles. Although military applications are the primary focus of the project, the company is also considering a civil passenger variant of the aircraft.

The most recent design studies have centered on the flight-control system. A 21-foot-diameter dome simulator is used for cockpit layout design and control laws. Urban Aeronautics also uses the simulator to investigate operational aspects such as the ability of several X-Hawks to work alongside one another in a narrow place.
Last December, a 30-pound-mtow, electrically powered model dubbed the Panda got airborne. The bigger (unmanned) Mule is slated to fly late this year with a Turbomeca Arriel 1D1 turboshaft engine. The full-size X-Hawk demonstrator is expected to make its maiden flight in 2010.

The two rotors are located fore and aft of the cabin. Two smaller shrouded rotors act as thrusters. Inspired by the Piasecki Flying Jeep of the 1960s, the shrouded-rotor aircraft is designed to operate in a city without the dangers usually associated with open rotors. For example, the design allows operation right up to the side of a building. A significant drawback of this type of rotorcraft is its fuel burn, which is much higher than that of a helicopter.

The main rotors have a diameter of 8.2 feet and they rotate at 1,800 rpm. Each of the two engines can drive all four rotors for lift and propulsion, in a conventional redundant architecture. Fuel is stored in the center fuselage, below the cabin floor.

A major improvement over early concepts for shrouded-fan vehicles is the addition of a vane control system. The combination of two vane cascades, at the inlet and the outlet of the duct, makes the aircraft unusually maneuverable, according to its developers. The vane cascades, situated equidistant from the aircraft’s center of gravity, generate pure lateral forces that allow the aircraft to move sideways without rolling. This vane system also generates control power enough to counter strong wind gusts.

When the vehicle has transitioned beyond hover into forward flight and the ducts are no longer needed, the louvers at the front end of the forward duct and at the rear end of the aft duct seal the ducts when they would otherwise become a high-drag hindrance. Wind-tunnel tests indicated a maximum airspeed of 140 knots.

Connecticut-based AeroComposites has been tapped to develop the lift rotors. The first shipset is due in the first quarter. Urban Aeronautics, Bell and Penn State University are jointly conducting some risk-reduction research. However, the latter two are involved in the full-size military version only. In 2003, Urban Aeronautics flew a smaller, two-person aircraft based on the same concept and dubbed the CityHawk. Price of a civil X-Hawk would be in line with that of similarly sized helicopters–$6 million.