Of all the sub-segments of the general aviation market, the turboprop field is the only one not experiencing a marked increase of new development. At airshow after airshow, very light jets, personal single-engine jets, more powerful piston singles and light sport airplanes have garnered the greatest amount of attention. Turboprops, although one of the more efficient breed of aircraft, are not the shining stars of most product development departments.
The bright spots among new turboprop designs are Quest’s Kodiak, the only new clean-sheet turboprop recently FAA certified, and projects inspired by the amateur-built airplane community, such as Epic’s sleek Dynasty and Comp Air’s massive Model 12. None of the traditional OEMs like Cessna, EADS Socata, Hawker Beechcraft, Pilatus, Piper or Piaggio has revealed a new turboprop design. Hawker Beechcraft did announce two new derivative King Air models earlier this year and Pilatus is near certification of its upgraded PC-12, but other than those projects, activities in the turboprop world are fairly static.
What is not static in the turboprop segment, however, is sales. Turboprops are one of the stronger players in what has been a fairly robust new aircraft sales market during the past few years. The latest figures from the General Aviation Manufacturers Association show that through the second quarter of last year, turboprop shipments climbed compared to the same period last year. In fact, every turboprop manufacturer saw an increase in shipments, to a total of 105 in the second quarter from 77 in the first quarter of this year. Percentage-wise, turboprops even outpaced jets in the first half, with shipments up 15.2 percent in the first half of this year versus the first half of last year. Jet shipments climbed 14.7 in the same period.
This seeming paradox raises the question of why is there so much design and manufacturing activity focused on jets when turboprops clearly remain popular for their lower operating costs and greater efficiency. Has turboprop design hit a plateau? Will the single-engine personal jet market take off next? As always, the marketplace determines the outcome, and in the next few years as personal jets achieve certification and entry-into-service, we will see if they displace airplanes such as the TBM 850 and smaller King Airs or if they create a new market segment of their own.
In Flight Test
Comp air 12
Early flight testing of Comp Air’s Model 12 single-engine turboprop revealed the need for some changes. The design philosophy of the airplane centers around the engine, according to Comp Air CEO Ron Lueck, who chose the largest turboprop engine he could find around which to design an airplane. Honeywell’s 1,650-shp TPE331-14GR is 25 percent more efficient than a comparable-sized Pratt & Whitney Canada PT6, he said.
The all-composite Comp Air 12 is designed to carry a full load of fuel and eight people including the pilot 2,535 nm with reserves. Total capacity will be a maximum of 10 people, including one pilot, and the interior will feature a lavatory. Price should be less than $3 million, Lueck said, and FAA certification and entry into service is planned for the first quarter of 2010.
Lueck flew the prototype Comp Air to the Sun ’n‘ Fun show in April, its first public appearance, and then to EAA AirVenture in Oshkosh, Wis., in late July. At Oshkosh, he noted that the conforming Comp Air 12 will have a fuselage 42 inches longer and four inches wider to better match the contours of the engine and cowling. The horizontal stabilizer will also grow 150 percent, he said. The first Comp Air 12 conforming to the revised design should fly by the end of the year.
Honeywell will likely be the Comp Air 12’s avionics supplier, with its Apex suite, the same choice that Pilatus made for the upgraded PC-12, Lueck revealed. “The only real competition [for the Comp Air 12] is the PC-12,” he said at Oshkosh.
Lueck said he plans to mount strain gauges inside the Model 12’s airframe to provide a real-time view of the forces on the airframe. This system will store up to 100 hours of information and help when it comes time to validate the airframe life to the FAA during the certification process, he explained.
Comp Air may build a production facility for the Model 12 near its headquarters in Merritt Island, Fla., but would also be willing to look elsewhere. “I would like to stay in Florida,” Lueck said, “but it’s not a necessity.”
Epic Aircraft has taken an unusual route to certification of new airplanes, choosing to launch various models as amateur-built versions and then gaining flight experience to tweak the design of the certified version. Epic is following this formula with the single-engine turboprop Dynasty, single-engine Victory jet and twin-engine Elite VLJ.
Epic plans to obtain Transport Canada certification first followed by FAA and EASA certification, and is working with the Canadian Centre for Aircraft Certification near Calgary, Alberta, to certify the Dynasty early next year. Thus far, the Dynasty program has logged 1,500 hours toward certification testing, according to Epic.
The composite six-seat Dynasty will sell for $1.95 million, just a little less than the projected $2.2 million price of the certified twin-engine Elite VLJ and half a million more than the planned certified price of $1.3- to $1.5 million for the Victory single-engine jet.
Farnborough Aircraft F1 Kestrel
Farnborough Aircraft is now expecting certification of its single-engine F1 Kestrel in 2010, pushing the date back from the previously planned 2008 schedule. The prototype, which first flew last July, has logged about 120 hours, according to Richard Blain, commercial director, including hops throughout the U.S. and Canada, cold-weather testing in Greenland and six months in Abu Dhabi for hot-weather trials. The prototype last traveled to England for modifications, Blain said.
The prototype has been invaluable to help design the final version of the F1 Kestrel, he said, adding that “it essentially will be a new aircraft.” Changes planned include a larger cabin, redesigned fuselage, wing structure and systems, additional fuel capacity and improved flap system. “None of those things are the result of major issues,” Blain said. The avionics suite has not yet been selected but will be a integrated glass cockpit. “We’re in discussions with a number of avionics providers,” Blain added.
The F1 Kestrel is a superb flying airplane, Blain enthused. “It has so much power and is such a gentle giant. It’s extremely responsive and coordinated, a pussycat on the one hand and a rocket ship on the other. Field performance is exceptional.”
Farnborough Aircraft is planning the next prototype, “which will be close to the conformal design,” Blain said. “Most of the engineering efforts are centered in the UK, but we’re not discounting building it or taking production elsewhere.”
Hawker Beechcraft King Air C90GTi and B200GT
Hawker Beechcraft announced two upgraded King Airs at the EBACE show in Geneva last May, the King Air C90GTi with an upgrade to Rockwell Collins Pro Line 21 avionics and the King Air B200GT with more powerful engines. The new avionics package in the C90GTi brings that airplane to the same avionics level as its siblings, the King Air B200 through the Hawker 900XP.
The Pro Line 21 installation in the C90GTi includes three large-format LCDs, digital radio and audio systems, multi-sensor FMS, solid-state weather radar, Collins Chart Link chart-selection system, monitoring of onboard systems and optional Jeppesen charts, XM weather, Universal graphic weather for international operations and Rockwell Collins HF radio.
Hawker Beechcraft has released performance figures for the re-engined B200GT, and its 305-knot maximum cruise speed is 20 knots faster than that of the B200. The more powerful engines also enable faster climb rates. According to Hawker Beechcraft, the B200GT’s PT6A-52 engines were designed specifically for the new King Air, by “mating the turbine section of the 1,050-shp capable PT6A-60A found on the King Air 350 with the existing King Air B200 PT6A-42 gearbox.” An added benefit of the new engine is that it does not have the 10,000-foot takeoff field altitude limitation that applies to the B200.
Certification and first deliveries of the B200GT are scheduled for the third quarter of this year, followed by the new C90GTi in the fourth quarter.
India’s National Aerospace Laboratories continues to make progress with its twin-turboprop Saras light transport aircraft. The second Saras, PT-2, made its first flight on April 18 in Bangalore, flown by R.S. Makker as chief pilot, A. Malik as copilot and M.S. Ramamohan as flight test engineer. The flight lasted 40 minutes, with a climb to 9,000 feet and maximum speed of almost 150 knots.
Saras’ PT-2 features larger engines, the 1,200-shp Pratt & Whitney Canada PT6-67A instead of the 850-shp PT6-66 that flies in PT-1. Other improvements over the original Saras, which logged 106 flights since its first flight in May 2004, include larger-diameter propellers, modified structure for the larger engines and flight control, electrical and avionics systems modifications. The need for the larger engines, according to NAL, is to meet FAR Part 25 one-engine-inoperative climb gradient requirements. “All these improvements have brought the PT-2 much closer to the final production-standard aircraft,” NAL stated.
NAL plans on building one more prototype to final production standards, but also incorporating weight-reduction techniques to trim 1,100 pounds from the airframe. Methods used to reduce weight will include, according to NAL, “optimization of metallic structures, stringent fabrication control [and] increased use of composites.”
This could include in the PT-3 version all-composite wings and empennage.
Pilatus PC-12 Next Generation
The newest version of the Pilatus PC-12 has spent a lot of time flight testing its new Honeywell Apex avionics suite at Honeywell facilities in Kansas and Phoenix, in preparation for certification later this year.
The PC-12 Next Generation is a major step for Pilatus, upgrading the avionics to an integrated system based on the Honeywell glass cockpit. The four-screen (two PFDs and two MFDs) Apex system will display not only flight information (including weather, charts and flight planning functions) but also engine and aircraft configuration data. It will also be used to control pressurization and environmental systems.
Pilatus hired BMW Group DesignworksUSA to design the new cockpit. The Next Generation PC-12 also has a more powerful Pratt & Whitney Canada PT6A-67P engine, with 15 percent more thermodynamic power than the original PC-12’s PT6A-67B.
Other enhancements include digital dual-zone environmental control system, automatic digital cabin pressurization control system and a fully redundant power generation and distribution system, according to Pilatus.
In Development Evektor EV-55 Outback
Evektor has begun prototype assembly, including subassembly production, of the nine-passenger unpressurized twin-turboprop EV-55 Outback. The manufacturer said it submitted its application for a type certificate during a meeting between the certification team and regulatory authorities at the company’s facilities in Kunovice, Czech Republic.
Evektor also plans a float version of the Outback, plus a full cargo configuration capable of carrying standard cargo containers and a combo version for cargo and four passengers.
The EV-55 program has been delayed pending new financial backing, said marketing manager Milan Morkus. “In spite of the fact that we are still in the stage of building the first prototype the demand of potential customers is enormous.”
FAA certified last February, Aero Vodochody’s Ae270 single-engine turboprop has not made much progress since then. Aero Vodochody was purchased by private equity firm Penta Holding early this year and recently returned to profitability, thanks to contracts with Sikorsky on the S-76 and a separate military L-59 overhaul program.
Aero Vodochody and Taiwan’s Aerospace Industrial Development Corporation share a joint venture in Ibis Aerospace, which was supposed to work on a refined version of the Ae270 with redesigned wings and systems, but this project was awaiting discussion between Aero Vodochody and AIDC, which is also dealing with funding problems involving its investment in Sino Swearingen Aircraft.
Utilicraft Aerospace Industries has recently received new funding and is re-embarking on its plans to build the dedicated twin-engine cargo-hauling FF1080-300ER. As an interim step, Utilicraft has cut metal on the smaller -200 design, which will act as a 77-percent scale prototype for the larger -300.
First flight of the -200 is planned for January. Subcontractor Metalcraft Technologies in Cedar City, Utah, is building the -200 fuselage, and another company (to be named) will manufacture wings. The large subassemblies will be shipped to Utilicraft’s Albuquerque, N.M. facility for final assembly.
Unique features of the all-aluminum FF1080-300ER are the ability to carry standard-size cargo containers that are also used by larger cargo airplanes. Making the pilot’s job easier is a pressurized cockpit; the cargo bay is unpressurized.
Vulcanair Aircraft AP68TP-600 A-Viator
Vulcanair, which purchased the type certificates and assets of Partenavia in the late 1980s, is reintroducing the turboprop Viator as the new A-Viator. First deliveries are expected to begin late this year. Vulcanair plans to include glass cockpit avionics that are a combination of two large displays–one for the pilot and one for the copilot–fed by Garmin navigators and transponder.
The all-aluminum A-Viator will offer a variety of interior configurations, from 11 occupants in high-density seating to combination passenger/cargo, medevac or parachute jumping layouts.
Certified Quest Kodiak
The FAA awarded type certification to Quest’s robust single-engine Kodiak utility turboprop on May 30, but facing initial limitations on the airplane, Quest didn’t publicize the certification until most of the limitations were removed in mid-July.
Quest has applied to the FAA for a production certificate, which would help speed issuance of each airplane’s airworthiness certificate and reduce the company’s dependence on FAA inspectors. With a backlog of more than 100 Kodiaks, the company hopes to deliver the first customer airplane this month or next month, and then one a month for the next six months and two per month after that. When Quest eventually is able to ship two airplanes a week, the manufacturing rate will match the rate of orders being received, the company said.
The Kodiak is now approved for day/night VFR/IFR operations, but has some remaining limitations on its type certificate that will soon be lifted. One is a 1,000-hour life limit on the airframe that will be removed once fatigue testing is completed in about a year, well before any operator reaches that number. Some actuators have been limited to operations in temperatures no colder than -25 degrees C, but the plan is to revise that to -55 degrees C so that operators won’t be limited in far northern and southern climes. Certification of options like the S-Tec autopilot and belly cargo pod is nearly complete. A TKS de-icing system will also be available, with the goal of flight-into-known-icing certification.