New Turboprops

 - August 30, 2007, 7:03 AM

Of all the subsegments of the general aviation market, the turboprop field is the only one not experiencing an increase in new development. At airshow after airshow, very light jets, personal single-engine jets, more powerful piston singles and light sport airplanes have seen the greatest amount of activity. Although turboprops are one of the most efficient ways to fly, they are not the shining stars of most product development departments.

The only bright spots in 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– Cessna, EADS Socata, Hawker Beechcraft, Pilatus, Piper or Piaggio–is publicly working on any new turboprop designs. Hawker Beechcraft did announce two new derivative King Air models earlier this year, and Pilatus is near certification of its upgraded PC-12, but for the most part, activities in the turboprop world are fairly static.

What is not static in the turboprop segment, however, are 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 this year, turboprop shipments climbed over the same period last year. In fact, every OEM selling current business aviation turboprops saw an increase in shipments, to a total of 105 in the second quarter of this year from 77 in the first quarter. Turboprop shipments even outpaced jets in the first half, with shipments up 15.2 percent over the first half of last year. Jet shipments climbed 14.7 percent in the same period this year. 

Why is there so much design and manufacturing activity focused on jets when turboprops clearly remain popular and offer 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 designed the airplane around the largest turboprop engine he could find. 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, then to EAA AirVenture in Oshkosh in late July. At Oshkosh, he noted that the production-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 by 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 plans to mount strain gauges inside the 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 might 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,” he said, “but it’s not a necessity.”

Epic Dynasty
Epic Aircraft has taken an unusual route to certification of new airplanes, launching various models as amateur-built versions then using the data accumulated as the owner-built airplanes gain flight experience to tweak the final design of the certified version. The company 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. 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, 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 expecting to certify 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 flights throughout the U.S. and Canada, cold-weather testing in Greenland and six months of hot-weather tests in Abu Dhabi. It is in England now for modifications, Blain said.

The prototype has been invaluable to help design the final version of the F1 Kestrel, he said, adding, “It essentially will be a new aircraft.” The final version will have a larger cabin, a redesigned fuselage and wing structure, an improved flaps system and more fuel capacity. The company is also implementing systems for more efficient manufacturing. “None of those [changes] is the result of major issues,” Blain said. The manufacturer has not yet selected an avionics suite, but it has determined that it will be an integrated glass cockpit. “We’re in discussions with a number of avionics providers,” Blain added.

According to Blain, the F1 Kestrel is “a pussycat on the one hand and a rocketship on the other. Field performance is exceptional.”

Farnborough Aircraft is planning the next prototype, “which will be close to
the conformal design,” he said. “Most of the engineering efforts are centered on the UK, but we’re not discounting building it or taking production elsewhere.” Farnborough Aircraft has partnered with Gamco on the Kestrel program, but Blain couldn’t say at this point how that will affect the location of prototype and production work.

Hawker Beechcraft
King Air C90GTi and B200GT

Hawker Beechcraft announced two upgraded King Airs at the EBACE meeting in May–the King Air C90GTi with new 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, multisensor 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 the company, 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.

NAL Saras
India’s National Aerospace Laboratories (NAL) 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 chief pilot R.S. Makker, copilot A. Malik and flight-test engineer M.S. Ramamohan. The flight lasted 40 minutes; the airplane climbed to 9,000 feet and achieved a maximum speed of almost 150 knots.

The Saras PT-2 features larger engines than the first airplane. On the second Saras the 1,200-shp Pratt & Whitney Canada PT6-67A replaces the 850-shp PT6-66. 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 larger engines, according to NAL, are necessary for the airplane 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 said.

The company plans to build one more prototype to final production standards and trim 1,100 pounds from the airframe. According to NAL, methods used to reduce weight will include “optimization of metallic structures, stringent fabrication control [and] increased use of composites.” The PT-3 version could include all-composite wings and empennage.

Commenting on the first flight of the Saras PT-2, chief test pilot Makker said, “The [airplane] is a graceful, potent and powerful flying machine.”

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 Honeywell’s Apex glass cockpit.

The four-screen (two PFDs and two MFDs) Apex system will display flight information (including weather, charts and flight planning functions) as well as engine and aircraft configuration data. It will also be used to control pressurization and environmental systems.

Pilatus hired BMW Group Designworks- USA 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 PC-12’s current 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 high-wing EV-55 Outback. The company said it submitted its application for a type certificate during a meeting between the certification team and regulatory authorities at its facilities in Kunovice, Czech Republic.

Evektor also plans a float-equipped version of the Outback, as well as a full cargo configuration capable of carrying standard cargo containers and a combi 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 from potential customers is enormous.”

Extra Aircraft EA-500
Extra Aircraft is focusing on the European market for the EA-500 single-engine turboprop, according to CEO Ken Keith, pending necessary infrastructure to support deliveries to the U.S. “The U.S. is a big market, but we’re a small company,” he said. Extra has begun the U.S. certification process, he added, “but we haven’t pushed it because we’re so focused on Europe.”

Grob Aerospace
G140TP and G160 Ranger

Both of Grob’s single-engine turboprop designs are on hold, according to the company, while Grob Aerospace focuses on development and certification of the SPn utility jet.

Ibis Ae270B
Aero Vodochody’s Ae270 single-engine turboprop has not made much progress since it received FAA certification in February 2006. The company 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 helicopter and a military L-59 overhaul program.

Ibis Aerospace is a joint venture between Aero Vodochody and Taiwan’s Aerospace Industrial Development Corp. (AIDC). The company 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.

Intracom GM-17 Viper and DS-12
Intracom announced a few years ago the GM-17 Viper, a Russian modification of a pressurized Piper Navajo with a single Walter M601E turboprop engine in the nose.
While no news has recently come from Intracom, a new airplane–the high-wing single-engine turboprop DS-12–has been added to the company’s Web site. No information about the planned engine, performance specifications or certification plans was available, however.

Utilicraft FF1080-300ER
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, the company has cut metal on the smaller -200 design, which will act as a 77-percent-scale prototype for the larger -300 program.

First flight of the -200 is planned for January. Subcontractor Metalcraft Technologies of Cedar City, Utah, is making the -200 fuselage, and another company (to be named) will manufacture the wings. The large subassemblies will be shipped to Utilicraft’s Albuquerque, N.M. facility for final assembly.

The all-aluminum FF1080-300ER can carry standard-size cargo containers that are also used by larger cargo airplanes. The cockpit is pressurized; the cargo bay is not.

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 (the VF600W Mission) 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 a 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.


Quest Kodiak
The FAA awarded type certification to Quest’s robust single-engine Kodiak utility turboprop on May 30, but there were some initial limitations on the airplane at that time so Quest didn’t publicize the certification until mid-July, when most of the limitations were removed.

“We’re very grateful for the people who helped us get here,” said Paul Schaller, CEO, praising suppliers such as Pratt & Whitney Canada and Garmin that helped a small airplane manufacturer–“we’re small potatoes to them,” he said–and its employees, “who worked really hard.” When the FAA cleared the early certification limitations on July 18, Quest held a barbecue for everyone involved. “It was a big emotional milestone,” Schaller said.

The company has applied to the FAA for a production certificate, which would help speed up issuance of each airplane’s airworthiness certificate and reduce the company’s dependence on FAA inspectors. The company has an order backlog of more than 100 Kodiaks. Schaller expects to deliver the first customer airplane this month or next, then one a month, and in six months, two per month.

When Quest is able to ship two airplanes a week, the manufacturing rate will match the rate of orders, he said.

Quest’s goal is to serve the mission-aviation market, and to that end the company sought funding from missionary organizations early in the program. Every tenth Kodiak is dedicated to one of those missionary customers, which gets the airplane at cost. This system benefits Quest and the missionary customers, who have an incentive to promote the Kodiak because the faster the airplanes sell, the sooner the missionaries will receive their discounted airplanes.

Kodiak sales are factory direct, and Quest will provide the training as well. Schaller sees many benefits in staying close to customers by retaining control of sales and training. For example, the company will be able to customize the training to individual buyers’ needs instead of forcing Kodiak pilots into a one-size-fits-all training regimen.

Quest is setting up a service network for Kodiaks, but the company’s technicians will do the first 100-hour or annual inspection. “It allows us to check [the
airplane] out and be sure that it’s functioning correctly and catch any problems,” Schaller said.

According to Schaller, the Kodiak fills the needs of a variety of markets. “Ours is a whole bunch of little segments. The challenge is how to cost-effectively market to each segment,” he said. Whereas a manufacturer might expect some word-of-mouth activity surrounding a popular aircraft used by many of the same type of operator, Quest sees its single-engine utility turboprop going to different operators who don’t communicate with each other. As Schaller put it, “Guys who fly jump planes don’t talk to missionaries.”

The Kodiak is approved for day/night VFR/IFR operations, but has some remaining limitations on its type certificate that are expected to be lifted soon. 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 operators won’t be limited in far northern and southern climes. Certifications of options such as the S-Tec autopilot and belly cargo pod are nearly complete. The company said a TKS de-icing system will also be available, with the goal of flight-into-known-icing certification for the turboprop.

'New Turboprops' PDF