Business Props and Turboprops About to Enter the Marketplace

A “new generation” incarnation of the Soviet-era Let L 410 is overdue for delivery to its first customer, even as steady production of earlier versions continues in the Czech Republic for worldwide operations – not least in Russia. In an eight-year program costing $26 million, AI substituted 850-shp General Electric H85-200s for the original Walter M601s, Garmin G3000 avionics, modernized cabin, a new wing with integral fuel tanks, and a longer nose having doubled baggage space – and flew the result in July 2015. EASA certified the NG on Dec. 19, 2017, and the FAA followed suit on Jan. 10, 2018. Series manufacture was formally launched on March 1, 2018, with the stated aim of completing the first (MSN 5001) before the end of that year. It is still awaited.

Performance improvements include generally enhanced hot-and-high characteristics; flight lifetime doubled to 30,000 hr.; maximum cruising speed of 227 kt.; max fuel range of 1,388 nm (making wingtip tanks optional, rather than obligatory); and endurance of over 10.5 hr. Engines are geared to turn the Avia AV 725 five-blade propellers at slower speeds, for reduced noise; and payload is 4,748 lb. in the form of 19 passengers or equivalent freight, although executive transport conversions are a further possibility.

Based in Temecula, Calif., Ampaire uses Cessna’s early-’60s, twin-tailboom, push-pull Model 337 Skymaster as the basis for an electric-powered six-seat utility transport. The name derives from the power source, and the fact that if viewed upside down and read backward through a mirror “337” resembles “EEL.” Be that as it may, cofounders Kevin Noertker and Cory Combs offer removal of the rear Continental IO-360-G piston engine and substitution of an electric motor and batteries. Both power sources are intended to operate simultaneously for a range estimated as 174 nm.

On June 6 of this year, Ampaire made the first public sortie by a previously flown “parallel hybrid” aircraft converted from a 1973 Skymaster II, N72342, retrofitted with Horton STOL winglets. Production conversions will be available from 2021.

However, the first Electric EEL customer, Personal Airline Exchange (PAX), which ordered 50, plus 50 options, as announced on June 22, will get the feel of the 337 by employing two standard machines on air taxi services beginning early next year. A second hybrid prototype will soon begin experimental services with Mokulele Airlines of Hawaii, flying guest passengers in advance of certification; and a similar tryout is planned with Vieques Air Link of Puerto Rico.

Non-U.S. rights to the large kit-built projects of the previous Epic Aircraft in Bend, Ore., were sold to China Aviation Industry General Aircraft in a bargain bundle in 2010. The Epic LT and slightly smaller five-seat Escape turboprops then became the Primus (later Navigator) 100 and 150, respectively, to be manufactured in Zhuhai for fly-away sale only. First to emerge, the 150 had been rebranded as the Leadair AG300 when it made its “official” first flight on July 5, 2014, powered by an 850-shp General Electric H85 turboprop. Certification in 2015 and a $1.5 million price were then confidently advertised for an aircraft capable of 1,350 nm and a cruising speed of 324 kt.

While a static test airframe passed its trials in May 2016, the two preproduction AG300s assigned to certification flying have failed to materialize, although the program is still advertised as active by Avic General Aviation. Therein could be a clue to the delays, because offered range has now shrunk to 972 nm, and cruising speed to 270 kt. Max takeoff weight has been upped 500 lb. to achieve a “commercial load” of 1,000 lb.

Because of program slippage, last year’s NBAA Convention in Orlando had to make do with a fuselage mockup in the static park instead of an anticipated prototype Denali. The promised first flight date of early 2019 (assuring certification to FAR Part 23 [single pilot] and service entry in 2020) has also been and gone. However, at EBACE, Geneva, in May, Textron confirmed that the prototype and the first two production-conforming aircraft will be used in the flight test program “set to begin later this year, where the three ground test articles will be used for the company’s airframe static and fatigue tests, and for cabin interior development and testing.” The Denali will be built in Wichita on the line vacated by the transfer of Caravan production to Independence, Kans.

One all-new, 1,300-shp General Electric GE93 Catalyst single-power-lever turboprop drives Denali’s McCauley Blackmac five-blade, carbon-composite reversible propeller and makes the $5 million utility transport good for a 1,100-lb. full-fuel payload, 285-kt. maximum speed and 1,600-nm range with four passengers. The 5-ft.-3-in.-wide pressurized cabin, 4 ft. 10 in. high and 16 ft. 9 in. long, is accessed via a forward door or rear freight door (4 ft. 2 in. wide) and has seating for a typical six executive passengers and two pilots, although nine-plus-two represents maximum occupancy. Cabin atmosphere is 6,130 ft. at 31,000 ft.

Avionics are based on Garmin’s three-screen G3000 suite, with weather radar, synthetic vision, dual FMS and dual WAAS-enabled GPS receivers for navigation, dual transponders with ADS-B In and Out, TAWS-B, TCAS I, dual AHRS and dual air data computers.

A production license for the former Iowa-based King’s Angel 44 pusher twin-prop was acquired in 2013 by Hubei Taihang Xinghe Aircraft Manufacturing of China. In May 2016, the Hubei local government provided funds to establish a manufacturing plant.

Originally, the King’s Engineering Fellowship managed to place only four aircraft between its 1984 first flight and 2008. Two 300-hp Lycoming IO-540s propel this six-seat STOL machine at 169 kt. on 65% power, covering 1,248 nm at the same setting, or 1,720 nm on full economy. The first Chinese example, built by Taihang, was substantially complete by 2016, but nothing transpired until Chenlong Aircraft (Jingmen), a different company, announced in June 2019 that its first Chinese-built Angel was anticipating a maiden flight at Weihe Airport, Jingmen. Chenlong lays claim to the FAA type certificate, production license and airworthiness certificate of the Angel, although the current FAA TC holder is the King’s Aviation Fellowship of Orange City, Iowa. A revised order book now claims three from the Philippines and 30 Chinese “intentions.”

Rollout of the initial production Seastar was at Oberpfaffenhofen, Germany, in August 2017, but the amphibian appears to have failed to meet its planned maiden flight date in the first half of this year. Airborne trials will be for revalidation of its 1990 type certificate, by reason of several upgrades including a Honeywell Primus Epic 2.0 cockpit, new five-blade MT propellers, new landing gear from Sumitomo, and a water-maneuvering thruster.

The Dornier family’s 1980s company was reborn in 2015 with the assistance of Chinese money, having previously built only two (arguably three) prototypes of the 12-passenger, push-pull (PT6A) turboprop in its previous incarnations. Now employing composite parts supplied by Diamond Canada (also a Chinese-controlled company), the airplane sells for $7.5 million, cruises at 180 kt., and has a range of 900 nm. A government surveillance version, named Orca, was launched in May 2019, for 2022 availability.

On Nov. 9, 2018, with workshop assistance, the 54th and last constructor-customer of the Epic LT received his airplane’s airworthiness certificate. The E1000 factory-produced version now moves to center stage, albeit slowly. A second, production-conforming E1000 prototype flew on Jan. 23, 2018, and completion of static testing was announced on July 25 of that year. Type inspection authorization (TIA) – a preliminary to FAA certification – was delayed a year for undisclosed reasons, not being announced until July 22, 2019, but Epic is still promising E1000 type- and production-certification before the end of this year.

Russian-owned, Oregon-based Epic flew its first E1000 in December 2015, and despite the loss of some early Russian orders, has “over 80” customers, from Canada to Australia, lined up for its $3.25 million, PT6A-67A-powered offering.

Operators get a carbon-fiber airframe, six seats, pressurization, a three-screen Garmin G1000 NXi EFIS, autopilot, 1,650-nm economy-cruising range with 1,100-lb. payload, 320-kt. normal cruising and 34,000-ft. ceiling. Compared to the LT, there are numerous certification-related upgrades, including a redesigned electrical system; an emergency exit; stick shaker/pusher; engine-driven hydraulic system pump (from electric/hydraulic) for quicker landing gear retraction; deicing boot on wing leading edge; automatic fuel valve; and aerodynamic refinements.

Large as life, the Alice prototype – admittedly not yet flown, and a year behind schedule – was a prominent feature of the static display at Paris this June. The innovative Israeli electric airplane is powered by three pusher propellers with combined output of 800 kW (1,070 shp): the main between its V-tail and steerable tailwheel; two auxiliaries at the wingtips, where they assist aerodynamic efficiency. System testing is to be conducted at Prescott, Ariz.; flight testing primarily at Moses Lake, Wash.

A second prototype is expected imminently and a third, production-conforming aircraft in mid-2020. Type certification is due by the end of 2021 and initial deliveries in 2022, both targets subject to the small matter of a $200 million investment that Eviation was soliciting in Paris. Cape Air of Hyannis, Mass., is the commercial launch customer, with an order for an undisclosed “double digit” quantity, placed on June 18, 2019.

Of the 14,000-lb. max takeoff weight, 8,380 lb. is batteries sufficient for a range of 565 nm, plus IFR reserves, at 260 kt. Seating is for up to nine passengers, plus two crew, in a pressurized cabin, despite which, cruising altitude is a modest 10,000 ft. After a late swap, avionics are Bendix/King.

South African Pegasus Universal Aerospace began international marketing of its Vertical Business Jet (VBJ) at EBACE, Geneva, in May, when a 12% scale model was shown. A full-size prototype was then scheduled to fly in 2020, contingent upon receipt of some of the “at least $400 million” needed to reach the production stage. Three General Electric CT7-8 turboshafts, each of 2,300 shp, power vertical and horizontal fans by direct drive and gearboxes, bestowing the ability to operate from both heliports and conventional runways. Accommodation is for between six and eight passengers, including one beside the pilot. Estimated performance includes 410-kt. max level speed and ranges of 1,150 nm in VTOL mode or 2,380 nm as an airplane.

After a decade of tribulations, not entirely shaken off, John Meekins’ conception of an ideal six-seat amphibian took to the skies of Titusville, Fla., on Aug. 6, 2018. Having come close to being abandoned four years ago, it was revived at the insistence of potential buyers in Brazil, Canada, Chile, China, Dominican Republic, France, Indonesia, the UK and elsewhere. Comp Air Aviation was then engaged to finish the prototype, although the matters of certification and series production have yet to be resolved.

Built of carbon fiber, and configured with an unusual twin-tailboom and float arrangement to lower the center of gravity and reduce the risk of overturning, the sleek Privateer has a pusher propeller turned by a Czech 724-shp Walter M601 turboprop. Cruising speed is estimated as 195 kt., and range, 870 nm. Progress has been slowed by the prototype’s heavy landing at Melbourne Airport, Florida, in March this year.

What used to be Groen Brothers, promoting small autogyros, has grown into SkyWorks, offering large convertiplanes in collaboration with Scaled Composites. Although prospective military versions of the VertiJet have aroused interest, Skyworks is also known to be considering a civil model seating between four and 12, cruising at 400 mph over a range of 1,000 nm. Don Woodbury, Skyworks’ chief technology adviser, describes it as “an aircraft that can take off and land vertically, hover when needed, and cruise with the speed, range and efficiency of a fixed-wing aircraft.” VTOL is, apparently, achieved by rotor tip-jets that do not appear on artists’ impressions of the design.

Like Ampaire in the U.S., VoltAero has selected the venerable Cessna 337 Skymaster as the basis of an electric six-seater, but the definitive Cassio 2 will be new-built in France from composites; available from late 2022; and a trimotor, with the front engine replaced by two wing-mounted propellers in forward extensions to the tailbooms. An “Iron Bird” static testbed, announced in October 2018, was shown at Paris in June. Using another converted 337, the four-phase Cassio 1 flight development program, in conjunction with Italian partners, is due to achieve approximation to production standard by the end of this year.

The definitive Cassio 2 will have a single 600-kW (805-hp) multifuel engine generating electricity for batteries powering three electric motors (two tractor and one pusher). Additionally, as a safety feature, the piston engine can be directly coupled to the rear-mounted pusher in an emergency. A stretched variant, with nine seats, is planned.

The 65% scale TriFan development machine, the 600-65 POC, missed its late-2018 first flight slot, but took to the air on May 2 on its initial, remotely piloted, tethered hovering exercises. A full-size airplane is due at the end of next year.

In a recent change of horses, XTI dropped the Honeywell HTS900 turboshaft it had selected two years ago and will now use the new, 1,300-shp General Electric GE93 Catalyst to power the electrical system turning three, five-blade ducted fans: two in the wing leading edges, swiveling through 90 deg. between hovering and forward propulsion (when wings provide lift); and one, fixed and thrusting vertically, in the rear fuselage, employed only during takeoff and landing.

With six seats, the TriFan 600 claims the speed, range and comfort of a luxury business airplane, combined with the capabilities of a helicopter. It will travel at 300 kt., reach 29,000 ft. in just 10 min. and then cruise in airplane mode over a range of up to 1,200 nm. Control is fly-by-wire, while carbon fiber and epoxy feature prominently in the structure.

Commitments to the $6.5 million TriFan currently stand at 81.