Nothing re-ignites interest in new turboprops faster than a good old-fashioned “fuel crisis.”

While no one thinks that the market will top the peak year for business and utility turboprops–1981, when 800 were sold–we are also far away from the 1996 trough of 100 aircraft. For the first six months of this year, turboprop deliveries were up 19.4 percent compared with the same period one year ago, according to the tracking report of the General Aviation Manufacturers Association (GAMA). This push also has affected the prices of used turboprops, up 15 to 20 percent since 2004, according to aircraft valuation company Vref. Some individual models, such as the King Air B200, did significantly better, gaining 44 percent in value between 2004 and the first quarter of this year. And while the overall used aircraft market has slipped recently, used turboprops are down the least of any segment this year, declining only 1.2 percent, according to Vref.Turboprop manufacturers are building the airplanes as fast as they can. New production of single-engine turboprops at Pilatus and Socata is basically sold out for the next three years; both companies are operating at a fixed capacity, with no plans to expand it. Due to EADS Socata’s trickle rate of TBM production–450 over the last 18 years–the airplane has enjoyed steady demand and dealers generally sell the airplanes before they even arrive on their ramps. Socata stepped up TBM 850 production to 52 last year.This “capped production” strategy leaves dealers and customers clamoring while adroitly preserving resale value, and the makers of twin turboprops are using the same plan. Hawker Beechcraft delivered 79 King Airs during the first half of the year, and not even the recently concluded five-week strike by company machinists should put much of a dent in deliveries or demand. The company is looking at significantly boosting King Air production next year. Overall among all manufacturers, new deliveries could easily top 500 this year.Upgrades of classic modelsEven as fuel prices retreat from their summer highs, no one thinks that jet-A will dip much below $5 a gallon, a fact that has left turboprop manufacturers unabashedly enthusiastic. So much so that existing models have been refreshed with uprated engines, improved glass-panel avionics and new interiors, even though their production numbers are low compared with those of business jets. Over the last two years, Hawker Beechcraft, Piaggio, Pilatus and Socata have all introduced “refreshed” models.Piaggio introduced a new interior on the Avanti II pusher twin earlier this year. It gives the cabin a smoother and more modern appearance. There is more room for storage and all the pieces go together more quickly. Cabin lighting was also updated. All upwash, downwash and aisle lighting has been modernized with LED. The PSUs are integrated for a cleaner look. A new acoustic insulation package reduces cabin noise. The lavatory cabinets and lavatory packet door were redesigned to provide more storage and better clearances. Piaggio also updated the in-flight entertainment options, which include the Rosen combination CD, DVD, moving map and MP3 unit. None of this refreshing comes cheap, but buyers do not seem to mind. New single- engine TBM 850s and Pilatus PC-12s fetch $2.9 million and $4.2 million, respectively, while new twins such as the King Air 350 and Piaggio Avanti are more than $6 million each, butting up against, and in some cases exceeding, the prices of new light jets. Increased demand has not created a mad rush to develop a truly new “clean sheet of paper” business/utility turboprop, although a handful are in development.