Turboprops are Back

Supply has dwindled and demand has risen. Here’s what’s driving the trend. 

This is the healthiest market for new turboprops in recent memory. Back in 2008, the last year before the wheels completely came off the global economy, members of the General Aviation Manufacturers Association delivered 538 turboprop aircraft. The number declined steadily in the following years, but in 2013, shipments of turboprops bounced back strong to a record 645 units. There is no shortage of new models—including some twin-engine ones—on the horizon. 

Meanwhile, the used-turboprop market has firmed substantially, with the fleet percentages for most models showing only single-digit availability and high pricing as a result. A 1981 Cessna Conquest II twin now trades for an astonishing 99 percent of what it cost when new, and some other models have held their value almost as well, according to the aircraft pricing service Vref. A 1985 Cessna Caravan single goes for 93 percent of its new price, while a 1991 TBM 700 sells for 85 percent of its original value and a 2008 TBM 850 sells for 81 percent. A 2009 Piper Meridian and a 1990 Pilatus PC-12 go for 75 and 74 percent of their new prices, respectively.  

For years, turboprops have suffered under the stigma sometimes called “prop aversion.” 

Back when different companies owned Beechcraft and Cessna, the latter unleashed a particularly brutal print advertising campaign directed at the former’s King Air turboprops with the headline “Shake, Rattle, and Roll.” It was funny, but not really fair. Flown properly, even when compared with jets, turboprops deliver a smooth ride. Maybe the cabin isn’t as quiet as a jet’s, but the difference isn’t huge. And on hops of 300 nautical miles or less, the difference in travel time between a jet and a turboprop is negligible. Plus, turboprops burn a lot less fuel, an important consideration even though oil prices have declined steeply of late. 

Another thing driving the turboprop resurgence is technology. Within the last two years, Beechcraft, Cessna, Daher-Socata and Piaggio Aero have all introduced turboprop models with significantly improved technology that cuts noise, landing/takeoff distances and climb times and increases payload, range, fuel efficiency and speed. Many of these changes are available as modifications to older-model aircraft as well. 

The biggest innovation is the swept-blade propeller (see sidebar below). Adding blades and giving them an aerodynamic twist and higher degree of sweep means the props can move more air at slower speeds and using less power. That means more thrust at the same power settings, cutting takeoff distances and climb times, while using less power during cruise flight for more range and ergo better fuel economy. And because the blades can turn slower while producing the same thrust, the engines run at lower power setting so there is less noise inside and outside the cabin. It’s a real game changer. 

Yes, turboprops are back and they are better than ever. If you need the short-field performance, payload and good operating economics they provide—take another look. You just might be surprised. 

Three Turboprops with Swept-Blade Propellers

As the accompanying article notes, swept-blade propellers can dramatically improve performance. These models offer prime examples:

Daher-Socata TBM 900. A new swept-blade propeller and an aerodynamic clean up allow this single turboprop a 3dB reduction in takeoff noise and a faster top speed of 330 knots. Other benefits include a more than 20 percent reduction in standard day sea-level takeoff distance (from 2,840 to 2,430 feet), a 10 percent improvement in climb rates (now 18 minutes to the 31,000-foot certified ceiling) and a boost in range from 1,585 to 1,730 nautical miles (with 45-minute reserve). 

King Air C90GTx. Beechcraft began adding the Raisbeck-Hartzell swept-blade propeller on new King Air C90GTx twins late last year. Raisbeck introduced them to the retrofit market for all C90 and E90 King Airs in 2013. The four-blade propeller has a 30-degree sweep and—at 96 inches—is six inches longer than the previous prop. It shortens the C90GTx’s takeoff roll by 600 feet to 1,984 feet and its landing roll by 10 percent over a 50-foot obstacle to 2,160 feet (1,580 feet with props in reverse). The new props also allow an RPM reduction for cruise power settings to 1750 RPMs, reducing cabin noise by 1.6 dBA to 74.6 dBA, a level found in most new luxury automobiles.

Piaggio Aero EVO. The propellers on this recently unveiled model dramatically cut the twin pusher’s notorious external noise signature by 68 percent (5dB) and give it a less obnoxious pitch. The changes also improve on the Avanti’s performance: maximum range increases by 17 percent to 1,720 nautical miles, and time to climb is reduced 3 percent as are emissions. 

Mark Huber, a private pilot, writes BJT’s aircraft reviews.