Finnoff Aviation Products has combined upgrades for the Pilatus PC-12 into a single offering called the Elite Performance Package, which includes a new engine, propeller, electrical bus-tie, and various battery options. The bundle saves buyers about $100,000, equivalent to the price of the propeller, according to Finnoff.
Available for the pre-2008 PC-12/45 and /47 models, the Finnoff package starts with replacing the original Pratt & Whitney Canada PT6A-67B engine in legacy PC-12s with the PC-12 NG’s PT6A-67P. While both engines produce 1,200 shp for takeoff, the -67B’s maximum continuous power is limited to 5 minutes, then power is limited to 1,000 shp. The -67P is fitted with power turbine blades made of a super-nickel alloy that is more resistant to creep and higher heat levels, and it can run at an interstage turbine temperature (ITT) of 820 degrees C. The -67P is limited to 850 degrees for 5 minutes, then it must be reduced to 820 degrees. The result for the modified PC-12 is a much faster climb rate, faster time to climb, and higher cruise speeds.
The engine upgrade cost is about $1.29 million and that includes a new engine and its five-year, 2,500-hour warranty plus free Eagle Service Plan membership. For an engine near overhaul time, paying for the upgrade may be worthwhile.
Typical overhauls cost $1.2 to $1.5 million, according to Finnoff, and some can be as high as $1.85 million. When an upgraded legacy PC-12 with the new engine goes on the market, the extra cost of the upgrade is generally recouped, the company said.
Swapping the engine in the PC-12 takes 10 to 14 days and 350 to 450 hours of work. There is some composite work and a larger NACA scoop on the cowl plus many wiring changes.
The upgrade package’s seven-blade MT composite propeller reduces vibration, lowers noise levels by 4 to 6 dB(A) and cabin noise by 6 to 7 dB(A), and improves climb performance, even without the engine upgrade. Finnoff flight testing documented a reduced takeoff ground roll, which is documented in the PC-12’s flight manual. With the seven-blade propeller alone, ground roll is 10% lower and takeoff distance over a 50-foot obstacle is reduced by 15%, although actual performance is better than the conservative numbers published in the manual.
Compared to the four-blade aluminum Hartzell propeller, the seven-blade is slightly less than 3 inches smaller in diameter. But the many blades still could interfere with a tow bar, so Finnoff designed a special tow bar adapter that slides underneath the blades and eliminates any interference.
With more blades, the new propeller has a smaller diameter, which provides more ground clearance and FOD protection. And there are no changes required to the engine or governor when installing the seven-blade propeller. Individual blades can be replaced if damaged, unlike some propellers where all blades would need replacement. Field repairs are also possible, and a damaged area on a blade can be fixed with an epoxy repair.
The electrical bus tie upgrade solves a limitation on the legacy PC-12s, which are equipped with two generators, one 300-amp and the other 120-amp. The existing bus tie is limited to 115 amps, and failure of the primary generator thus requires shedding electrical load to match the bus tie limitation. With the new engine installed and a 300-amp backup generator or a Finnoff upgrade to install the larger backup, the bus tie upgrade matches the PC-12 NG’s 220-amp limit, allowing the backup generator to carry much larger loads.
Battery options with the Elite package include dual lead-acid Concorde or single or dual True Blue Power TB-40 lithium-ion batteries. The advantages of the TB-40 batteries are their lighter weight and longer life, with no maintenance required for seven years.
To see the performance change to a legacy PC-12, Richard Phelan—chief pilot of Finnoff Aviation's sister company, Avex—demonstrated the difference between old and new in the company’s converted legacy PC-12, serial number 460. With four people on board and 2,700 pounds of fuel, the PC-12 weighed about 10,400 pounds, slightly below mtow.
We took off from Rocky Mountain Metro (KBJC) near Denver, climbed to 14,000 feet, and aligned so winds were perpendicular to our flight path. Continuing the climb through 16,000 feet, I started a timer to measure how long it took to climb to FL280 with power set at the 760-degree maximum ITT to simulate the legacy PC-12.
Total time for the climb was 14 minutes 30 seconds. Outside air temperature was ISA plus 12 degrees.
While level, we did some speed checks, and at the same simulated maximum power setting, true airspeed settled at 243 knots, with fuel burn 330 pph.
Phelan then pushed the power to 820 degrees ITT, the maximum continuous for the new engine, and fuel burn climbed to 370 pph while true airspeed notched up 21 knots to 264 knots. He pointed out that Pilatus pilots don’t typically fly at maximum power, preferring to trade longer engine life and lower fuel burn for reduced speed.
We ran the same test after descending to FL220. With power set to 760 degrees, true airspeed was 247 knots and fuel burn 380 pph. At 820 degrees ITT, true airspeed climbed to 273 knots and fuel burn was 420 pph.
Back at 14,000 feet, we returned to a climb attitude and I restarted the timer passing through 16,000 feet, with power set to 820 degrees ITT. This time, the climb took 10 minutes 50 seconds.
Phelan pointed out a key benefit of the more powerful PT6: faster climbs through ice-laden clouds. This is especially helpful in the Denver area.
Since New State Aviation Holdings purchased Finnoff Aviation last year, the three firms in the holding company’s stable—Avex, Blackhawk, and Finnoff—have expanded their offerings and services. The Elite package is the latest of the new products, but owners and operators of TBM, PC-12, and King Air series turboprops should expect to see even more interesting developments from the renamed holding company, now called the Blackhawk Group.