Turboprops continue to meet utility needs worldwide
Advantages include significantly less fuel burn, shorter runway needs, efficiency at lower altitudes, longer TBOs.
By Mike Potts
Pilatus PC12 was the first single-engine turboprop configured to compete with the turboprop twins in the business aviation market, offering comparable performance and cabin amenities.
Business aviation's turboprop segment is holding up reasonably well as the industry moves into 2011. The past decade has included some of the best sales years ever for turboprop aircraft. Turboprop deliveries, as reported by the General Aviation Manufacturers Association (GAMA), peaked at 535 units in 2008—the best year for turboprop sales since 1981, when 918 were delivered.
The years 2007, 2006, 2001 and 2000 all saw turboprop delivery totals above 400 units—a total not previously reached since 1984. And while sales have generally fallen with the rest of the industry in the economic downturn, manufacturers say they are optimistic about the prospects for turboprops. In a few cases, turboprop models have sold as well or better in the down economy than they did when things were booming.
The continuing success of the turboprop segment—which some had predicted might disappear as lower-cost jets became more available—is clearly a result of its diversity. Turboprops continue to perform a number of missions better than jets, including operations from short or unimproved fields, short stage lengths, and utility special missions beyond the scope of simple people-hauling from point A to point B. Also, in many applications turboprops are generally more fuel efficient than jets.
Eight manufacturers reported deliveries of business aviation turboprops to GAMA last year—Cessna, Hawker Beechcraft, Pacific Aerospace, Piaggio, Pilatus, Piper, Quest and Daher Socata. A 9th—Kestrel Aircraft of Brunswick Landing ME—has a new turboprop in development, so there are plenty of models for customers to choose from. All the turboprops currently in production use a version of Pratt & Whitney Canada's PT6A.
Generally, these airplanes fall into 2 categories—business transport, which includes Hawker Beechcraft, Piaggio, Pilatus, Daher Socata and Piper aircraft—and utility, which covers Cessna, Quest and Pacific Aerospace products. There is overlap in the categories, however, since almost all of these airplanes have some kind of special-mission application, and it isn't always easy to characterize exactly where these products exist in the market. A look on their websites usually tells who the manufacturers think they are competing against.
Introduced during NBAA 2010, the Hawker Beechcraft King Air 250 features improved speed and the runway performance the company says customers have been seeking.
Hawker Beechcraft Corp (HBC) has been the leading manufacturer of traditional twin-engine business turboprops since Beech introduced the concept in 1964 with the first King Air 90. Hawker Beechcraft VP Marketing and Communications Ron Gunnaron says the turboprop market has evolved over the years, but the reasons for operating a turboprop have not.
"The value propositions for these airplanes haven't changed," he says. "Whether it's a single or twin-engine turboprop, it's still all about moving more passengers for less fuel and carrying more payload than anything else can. The mission continues to be one of very high efficiencies."
Today HBC has 5 models of King Air in production—the 350i, 350ER (extended range), 350C (cargo door), 250 and C90GTx. It's a family of aircraft that Gunnarson says has been extensively upgraded in the past 10 years, with new engines, avionics, interiors and aerodynamic improvements that have increased speed, range and payload—all factors that keep them competitive.
All King Air models now feature Rockwell Collins Pro Line 21 avionics—and, with the introduction of the King Air 250, all are now equipped with winglets.
The C90GTx features the basic airframe configuration of the original King Air 90, with seating for 7–8 pax plus a single pilot. The addition of upgraded engines earlier in the decade (from the -21 version of the PT6A to the -135) boosted C90GTx cruise speed into the 270-kt range—up from barely 220 kts in the original 90. Maximum range is 1236 nm—up more than 200 nm from previous versions of the C90—while MTOW is increased by 395 lbs to 10,485 lbs.
Gunnarson points to product upgrades in the C90GTx as a major reason for its improving sales. Deliveries grew from 21 units in 2002 to 66 in 2008—a time when there was growing competition from single-engine turboprops as well as light jets.
The King Air 250 is the latest variation on the original T-tail King Air 200-series that Beech introduced in 1974. It replaces the B200GT, which had also received performance upgrades in the past decade, including new PT6A-52 engines that pushed its cruise speed into the 300-kt range. This was a step up from the 270-kt capability of earlier 200- series King Airs.
The 250 brings an increase in takeoff performance that Gunnarson says customers had been asking for. The 250 can now be operated at its 12,500-lb gross weight from runways as short as 2111 ft—500 ft less than a B200GT requires.
Top of HBC's turboprop line is the King Air 350, which is available in 3 versions and has emerged as the company's best-selling turboprop. The long-cabin 350, which features a double-club seating arrangement, is one of the few aircraft that can operate with both a full load of passengers and full fuel—a factor Gunnarson says has made it popular with flight departments using it to augment fleets of larger jets.
The 350i received an upgraded interior earlier in the decade, featuring materials and styling drawn from the company's Hawker line of business jets. The 350ER was introduced to make the airplane more attractive to the special-mission market, and extends the 350's already generous 1600-mile range out to 2200 nm. The 3rd version of the 350 has a cargo door. Last year the US government took delivery of 32 King Air 350s.
Gunnarson says most C90GTx models sold today are owner-flown, while almost all 350s are crewed by professional pilots. About half of B200GTs are owner flown, Gunnarson says, which represents a change from 20 years ago when most 200-series King Airs were professionally crewed. The primary turboprop competition for King Air sales, he says, comes from Pilatus and Piaggio.
Pilatus's PC12 burst on the scene in late 1994 as the first single-engine turboprop configured to compete directly in the business transport market with the turboprop twins. Its cabin is very comparable with the 200-series King Air—3 inches longer from the rear bulkhead to the flightdeck partition, 4 inches wider and the same height.
The PC12's performance is comparable, too, with a 280-kt maximum cruise speed and a 2650-ft runway requirement at sea level over a 50-ft obstacle on an ISA day.
In typical executive configuration the PC12 has 6 executive chairs plus a belted lavatory.