loading Loading please wait....

If you are a registered, please log in. If not, please click here to register.


Things certainly change over a year. A year ago the turboprop and jet segments seemed locked in a contest to see which could fall furthest in shipment declines. At the third milepost of the year in 2010- the turboprops prevailed slightly- down 20.8 percent (to the 20.3 percent drop the jet segment experienced)- and at the year’s final milestone propjets ended down 17.7 percent to the jets’ relatively smaller plunge of 12.3 percent.

Dave Higdon   |   1st December 2011
Back to articles
Dave Higdon Dave Higdon

Dave Higdon writes about aviation from his base in Wichita Kansas. During three decades in...
Read More

Turboprop Review (Part 1): An outline of in-production and in-development single-engine propjets.

Things certainly change over a year. A year ago the turboprop and jet segments seemed locked in a contest to see which could fall furthest in shipment declines. At the third milepost of the year in 2010- the turboprops prevailed slightly- down 20.8 percent (to the 20.3 percent drop the jet segment experienced)- and at the year’s final milestone propjets ended down 17.7 percent to the jets’ relatively smaller plunge of 12.3 percent.

For this year- the turboprop segment seems to have found a better footing- with the 2011 3Q GAMA numbers showing the category down the least of the three divisions (-5.9 percent) compared to the prior nine-month period. As has transpired before- turboprops managed to stave off the worst- even as they dropped every quarter compared to the same periods of 2010.

Why the slower decline? Why do propjets seem to periodically enjoy better times than the other two segments? Perhaps it has something to do with owner-flying. The top-selling propjets tend to be aircraft that are continually popular among pilots who fly for their own businesses- and find mission and personal fulfillment in a turbine aircraft that may actually costs less to own and less to operate that an older pressurized piston twin.

The preponderance of propjet aircraft enjoys single-pilot approval – in addition to the many positive attributes of the segment. Following are a few of the fleet-wide specifics for the turboprops- along with a detailed look at what the market offers now and for the future.

While exceptions exist anywhere we may deem to generalize- in general turboprop airplanes offer a common set of attractive attributes – the powerplants themselves responsible for most. For example- the typical turboprop engine in today’s airplanes boast TBO cycles of thousands of hours- with equally impressive inspection intervals.

Turboprop engines benefit today from propeller designs far more sophisticated than just a decade ago. The results: lower maintenance costs- longer overhaul cycles- improved climb and cruise performance – which- in turn- contribute to reduced noise levels. Complex scimitar designs deliver higher thrust on smaller diameters turning at slower speeds – all contributors to the listed improvements.

Specific fuel consumption numbers continue to improve- with the practical effect of allowing the use of higher power levels without suffering a proportional increase in fuel consumption (while consumption may be higher per-hour- the percentage increase is smaller than the percentage increase in power used). That- in turn- contributes to improvements in take-off- climb and cruise.

Then there’s the single-pilot operational simplicity engineered into even the multiengine propjets. The only exceptions to the sum total of these benefits exist among the un-pressurized models available – a small- important and dynamic segment of the propjet market.

Today’s propjets offer a broad range of turbine performance- propeller cost-effectiveness (some with at- or near-light jet cruise performance capabilities) with cabin and cockpit accoutrements that rival the best of the fanjet strata. We start now with a look at the wide array of turboprop singles- in production and in-development.

Caravans built today differ subtly from their originals first pressed into package-delivery service nearly 30 years ago. Cessna’s efforts have helped keep this brawny model contemporary and competitive. Well over 3-000 standard and stretched Caravans operate across the globe’s full range of climates – testament to its reputation as a heavy hauler with a sturdy airframe- single-engine simplicity easy handling.

Both of today’s original-body 208 and the stretched-fuselage 208B models fly behind the higher power of Pratt & Whitney Canada’s PT6A-114A (flat-rated to 675 horsepower). They also give pilots the huge capabilities of Garmin’s G1000 integrated cockpit- and both Caravan 208 models gained the TKS anti-ice system three years ago- solving some operational issues with the original anti-ice pneumatic boots system.

With its fuselage longer by four feet- the Grand Caravan offers major capacity gains over the original short-body model and imbues the 208B with seating for as many as 12 compared to the standard 208’s nine. Large aft-cabin doors let operators make full use of the Caravan’s space- along with the flat floor and tall ceiling. Millennium Concepts and Yingling Aviation offer the Oasis interior for those seeking to use the Caravan for corporate purposes.

In terms of payload capability- the short-body 208-675 offers 900 pounds of cabin payload when topped with 2-224 pounds of Jet A; the 208B’s full-fuel cabin payload jumps to 1-300 lbs. With pricing around $2 million – wholly dependent on options and which model you select – Cessna’s Caravan remains a leader within the single-engine propjet segment.

More information from www.cessna.com

A hot-performing single- the TBM 850’s 320- knot maximum cruise speed brings it to within 20 knots of a couple of entry-level jets. That’s pretty admirable- given that the TBM 850 achieves its speed from a single PT6A-66D powerplant – but nonetheless one that can make all 850 of its shaft horsepower right up to FL250. In addition- the TBM has a certified ceiling of FL310 (which it can reach in a mere 20 minutes)- and can cover 1-410 nautical miles – at that 320-knot max-cruise speed. Pull back the power to TBM 700 levels and the TBM 850 still pushes the 300-knot mark but range stretches to nearly 1-600 nautical.

The performance of the TBM 850 was exactly what Daher-Socata sought with its powerplant change four years ago. Of course- power and airframe refinements that show up in climb performance also show up on the runway. The TBM 850 can handle take-offs from runways well under 2-500 feet (2-100 feet at MTOW).

The front office of the single-pilot TBM 850 resembles that of a light business jet- with a three-screen Garmin G1000 integrated panel. Daher-Socata also equipped the TBM 850 to enhance safety and convenience with TAWS- TCAS- color weather radar- dual digital audio control heads and Garmin’s sophisticated GFC700 digital flight-control hardware.

More information from www.tbm850.com

Efforts to find a new U.S. home for the propjet single continue after plans for Montrose- Colorado- fell through. So as it stands Walter Extra’s German factory remains the only source for the Extra Aircraft EA-500- an appealing little propjet single.

The Extra 500 remains the only all-composite propjet flying – and the only one using Rolls-Royce’s 250 as the powerplant. The 250-B17F/2 coupled with MT’s five-blade composite propeller provides a formidable powerplant- one with a reversible propeller to help reduce landing distances. Exhaust heat provides anti-ice protection for the sleek engine inlet while the effective Goodrich Estane boots anti-ice system protects the lifting surfaces while imposing no aerodynamic penalties on the smooth airframe.

The Extra 500 can cruise over 1-600 nautical miles in ferry configuration- and can deliver cruise speeds as high as 215 knots at altitudes up to FL250 - its service ceiling. Factor the Extra 500 as an airplane ideal for the 350-to-500-mile legs- while offering potential to carry four in the cabin- two in the cockpit- and luggage for the trip.

More information from www.extraaircraft.com

Alan Klapmeier’s newest endeavor has a home- an engine- and - from the vibes at NBAA - a future. Kestrel made significant news at EAA AirVenture Oshkosh in July with the announcement that Honeywell’s 1-759shp TPE331-14GR- flat rated to 1-000shp would power the aircraft – assuring it of plenty of power up high in cruise- as well as on hot days at high-elevation runways.

The prototype works out of the new company headquarters/future factory at the old Brunswick Naval Station in Maine- while engineering work continues to progress in Duluth- Minnesota- where Klapmeier’s prior success story continues to build new Cirrus Aircraft.

The panel system remains undecided as of now- while engineers continue to tweak the cabin and wing designs. In its final form- Kestrel Aircraft plans to offer a six-to-seven-seat composite capable of cruising up to- or above FL300 with the ability to cruise at light jet speeds of 350 knots – and cover 1-000 nautical miles or more.

While development takes time- we expect to see a refined prototype some time next year. Final certification and list price remain unanswered questions.

More information from www.kestrel.aero

Whether you need an aerial SUV for hauling supplies into the outback or working space for an executive in the back- Pilatus’ fast- durable and efficient PC-12 NG covers the bases. From its STOL capabilities to its fast climb and high cruise speed- the PC-12 NG delivers on a broad array of mission needs. The PC-12 NG enjoyed a 15-percent gain in thermodynamic power over the original PC-12 model- along with the ability to continuously get the full- flat-rated 1-200 shp out of the PT6A-67P- and the reworked flight deck.

With the revised powerplant the PC-12 NG needs only 30 minutes to climb directly to FL280 and cruise at its maximum 280 knots. Along the way the PC-12 NG offers a range of more than 1-500 nautical (with full fuel and four on board) at altitudes up to FL300.

Adopting the Primus Apex integrated flight deck system from Honeywell imbues the flight deck with the most-desired touches for the savvy single pilot- while offering everything in pairs for two-pilot flying. The crew- single or dual- controls everything from the FMS to pressurization- datalink- charts- weather and radio tuning through the Apex MFD Controller with a dedicated Cursor Control Device (CCD).

The spacious cabin- meanwhile- offers room comparable to some mid-cabin jets while the cargo door expands access for oversize items. The reconfigurable cabin allows quick changes from the seating-for-eight space to one seating four that leaves the rest of the space available for cargo – whatever will fit through that big door. Further- the PC-12 NG should be able to visit almost anywhere you want- thanks to its short- 2-600-foot runway needs and its companion ability to get down and stopped in less than 2-000 feet.

More information from www.pilatus-aircraft.com

Piper’s propjet single continues to attract pilots while easing into its second decade of operation - and for good reason: Meridian is a solid performer and an adept single-pilot aircraft for the flight levels - and with development of the PiperJet Altaire suspended- the Meridian stands as the planemaker’s only turbine offering.

Fortunately for Piper- it’s an offering with enduring market appeal – as of the end of October Piper had delivered 23 so far this year- which is a significant gain over the 15 delivered through the first three quarters of 2010. The reasons behind the Meridian’s sales strength lie in its operational strengths and operating economies.

Performance-wise- many an owner/pilot covets an aircraft capable of cruising in the 260-knot range. The PT6A-42A- capable of making 850shp gets flat-rated to 500shp in the Meridian – and that power can be tapped continuously and as high as FL300- which is the Meridian’s service ceiling. That horsepower also allows the Meridian to use runways as short as 2-500 feet for departures (less for landing). The economy of that engine/airframe combination imbues the Meridian with the efficiency to cover legs as long as 1-000nm.

What counts for many- however- is what’s inside – and the Meridian offers an interior to enjoy- whether in the cabin or the cockpit - where the single-pilot operator enjoys access to a top flight panel- the Garmin G1000.

More information from www.piper.com

The latest to join our propjet pack- Idaho-based Quest Aircraft- accomplished something truly rare in General Aviation: starting a new company- creating- building and certificating a new airplane design…and selling them (more than 50 in total- and 10 so far this year).

Quest brought the KODIAK to market focused on a very demanding subset of utility operators – missionary and humanitarian aviation organizations who work in most of the world’s remote locations with some of the most-isolated populations on the planet. A contender in the utility-single niche long-dominated by Cessna’s Caravan- the KODIAK boasts plenty of space- lots of power – 700shp continuous- 750shp time-limited – out of the PT6A34 engine- good speed and decent legs.

Cabin- plus cargo pod offer 310 cubic feet of space and options include datalink weather and Garmin’s sophisticated Synthetic Vision System to enhance the pilot’s situational awareness up front. The G1000 is the standard stack in the cockpit panel. Cruise speed hits a solid 179 knots and the payload with full fuel is solid; put 900 pounds payload in the cabin and you can fly 900 nautical miles. The maximum range is just short of 1-000 nautical burning 50 gallons per hour (gph) at 172 knots. Pull back power to 34 gph and speed drops to 137 knots true- but the range jumps up to more than 1-100 nautical.

Capable of seating eight – plus the two on the flight deck – the KODIAK boasts options like special-duty interior finishes- oversize wheels and tires for rough-field duties and the TKS anti-ice system.

More information from http://questaircraft.com

That concludes our review of the single-engine Turboprops. Tune in next month when we will review the twin-engine props- including models from Hawker Beechcraft and Piaggio Aero.

Related Articles

linkedin Print

Other Articles