The ailerons have also been changed with the addition of a servo tab. Roll control force in the PC-12 has always been heavy, too heavy to harmonize with the pitch and rudder forces, but the new ailerons reduce force by as much as 60 percent at low airspeeds and up to 72 percent at high indicated airspeed. The servo tab moves opposite the direction of aileron travel, thus reducing control force in the same way a trim tab relieves force on a conventional control surface. Similar tabs were the norm on large propeller airplanes years ago, and even some jets, and are a good way to reduce forces without adding weight and complexity.
Other external improvements are a switch to LEDs for position lights, giving many thousands of hours of bulb life, and a new, smoother fairing of the dorsal fin to the fuselage.
Important changes have been made under the cowling since we last reviewed the PC-12, chief among them an engine condition monitoring system and an oil debris monitoring system. The condition monitoring system automatically records all important operating parameters of the engine and can provide early warning of any degradation so preventative maintenance can be performed. The oil debris monitoring system counts metal particles that circulate past a chip detector and issues a warning when a threshold is exceeded. A normal chip detector, which the PC-12 engine also has, uses a magnet to snag larger chips and then issue a warning, which is important, but the debris monitor can find a trend before a serious problem develops.
Much of the ready acceptance of flying such a large airplane on one engine comes from the unrivaled reputation for reliability of the Pratt & Whitney PT6A-67B engine that has powered all PC-12s. The engine is one of the largest in the PT6 family, producing 1,605 shp at sea level, but the PC-12 uses only 1,200 shp for takeoff and 1,000 shp for climb and cruise. That means full rated power is available for takeoff and climb even with air temperature at the takeoff airport above 120º F.
The design, workmanship and materials used to finish the PC-12 cabin have improved greatly over the years and now rival the interiors of other business airplanes. Most people order the airplane with six cabin seats, with a club arrangement forward. The huge baggage door in the rear is standard, so you can easily take your Harley along if you like, and the aft two seats can be quickly removed to carry oversize cargo. One very well done cabin feature is the potty that is located just aft of the copilot. What makes it work so well is that Pilatus devised a system of hard doors that fold out, sealing off the potty from both the cabin and cockpit, leaving plenty of space for comfortable use. It is one of the better potty arrangements in any light jet or turboprop.
New for 2006 are Ipeco pilot seats with their huge number of adjustments and long-term comfort. The seats are also more compact than the previous crew chairs, so there is even more room in an already spacious cockpit.