The Honeywell TPE-331-12JR powerplant. Photo credit to Honeywell.
Texas Turbine Conversions Inc. has begun delivering the first of its Cessna Caravan engine mods, and it’s a doozy. For $495,000, the owner of a model 208 or 208B (Grand Caravan) can exchange his or her stock, 675-shp Pratt & Whitney PT6A-114A turboprop engine for a 900-shp Honeywell TPE-331-12JR powerplant. Texas Turbines calls this mod the Supervan 900, and it comes with new engine mounts, a new cowling, new starter-generator, and a new Hartzell 110-inch diameter, four-blade propeller.
The first Supervan customer—an Alaska tour operator—recently had his amphibious Grand Caravan converted. Seven more Caravans are on deck for the conversion, including airplanes that will be based in Australia, Mexico, and Germany.
Texas Turbines’ Bobby Bishop says that compared to standard-issue Caravans, Supervan takeoff distances are cut by 25 to 30 percent. “I went up to Leadville [Colorado] and saw a 40-percent reduction in takeoff distance up there at 9,000 feet,” Bishop said. Texas Turbines says the Supervan’s ground run is 1,054 feet; standard Caravans list a 1,405-foot ground run.
But the performance improvements don’t end there. Max cruise at 10,000 feet is 198 knots, says Texas Turbines; standard Grand Caravans fly at 175 knots. Climb rate is 1,510 fpm at sea level and max takeoff weight, and max endurance is up to 1,000 nm, the company says. Another boost comes with the Honeywell engine’s 7,000-hour time between overhaul; the standard Caravan’s PT6 has a 3,600-hour TBO. The Hartzell propeller gives an extra inch of ground clearance on straight, non-amphibious Caravans.