ELECTRONICALLY REPRINTED FROM AUGUST 2018 www.bcadigital.com OF EDITORIAL EXCELLENCE Business & Commercial Aviation PILOT REPORT Pilatus PC-24 Pilot Report Pilatus PC-24 A business jet in a class all its own BY FRED GEORGE [email protected] than 400 lb. compared to using tradi- tional midsize aircraft turbofans. Being able to use lighter weight engines had a he much-anticipated Pilatus PC-24 might well be named trickle-down effect on overall airframe the big Swiss surprise. Many people confuse it for a tur- weight because beef can be taken out of engine mounts, support structures, bofan-powered variant of the PC-12. That would put it in wings and landing gear. the light jet class of the Cessna Citation CJ4 or Embraer APUs are virtually musts in midsize TPhenom 300, a market segment already overcrowded. aircraft, but Pilatus couldn’t afford the 300-lb. heft of the third engine. So, it worked with Williams to develop a But it’s actually a midsize jet with a a triple-disc brake for sure stopping. novel quiet power mode [QPM™] for the slightly larger cross-section than a Cita- The engines are mounted high on the right engine that reduces ground idle tion XLS+. Admittedly, it has 7 in. less aft fuselage to keep them clear of de- rpm while providing sufficient electri- headroom in the center of the cabin; bris kicked up by the tires. The flaps cal power for the vapor-cycle air condi- however, that’s because it has a con- have heavy gauge aluminum skins on tioner or electric cabin heaters when the tinuous flat floor rather than an 8-in. the bottom surfaces and they’re eas- aircraft is parked. dropped aisle. The main seating area is ily repaired. Final unimproved runway The right engine, operating in QPM, 2.7 ft. longer than in the XLS+, affording tests now are underway with approval comfortable seating for six people in the slated for later this year. standard executive interior. With 500 The quick-change interior is another cu. ft. of cabin volume, interior size alone distinguishing feature. In minutes, some puts the PC-24 into a midsize jet class or all of the chairs and furnishings can that’s sparsely populated, now that the be removed or repositioned, allowing Gulfstream G150, Hawker 900XP and the aircraft to be reconfigured as a four- most of the midsize Citations no longer seat passenger plus 200-cu.-ft. cargo are in production. combi, a double-club cabin for eight peo- “We wanted a small widebody,” says ple or a 10-seat commuter. All the chairs Chairman Oscar Schwenk. “In the begin- easily can be removed to convert for air ning, it was even wider. But that caused freight or air ambulance missions. too much drag. We think we have a good “Other aircraft in this class can be compromise now.” compared to the BMW 7 series or Mer- The PC-24, similar to the PC-12, has cedes S-Class,” says Bruno Cervia, who several exclusive qualities that arguably heads research and development for move it into a class of its own. The sig- Pilatus. “We wanted to build a Porsche nature feature is its 17-sq.-ft. aft cargo Cayenne.” door that swings up to provide access to It’s also the only business aircraft a 90-cu.-ft. aft, pressurized cargo com- priced under $23 million to have a laser partment. Incorporating the large door inertial reference unit, a key component into the aircraft design was no mean of an RNP 0.1-capable navigation sys- feat, considering the aircraft’s 8.8-psi tem. This, along with other standard pressurization system and strict empty avionics components, makes the aircraft weight budget. The proximity of the well positioned to take full advantage of wing trailing edge and rear-mounted the FAA’s and Eurocontrol’s 21st cen- engine air inlets to the cargo door posed tury air traffic management upgrades further challenges to Pilatus engineers. that are intended to make flying safer, The jet was designed from the outset more efficient and more environmen- for unimproved runway operations, un- tally friendly while increasing airspace like other jets aircraft adapted to that system capacity. role after certification. The rugged, Strict weight control enabled Pilatus trailing-link main gear are fitted with to fit the PC-24 with two Williams FJ44- four large, 73-psi tires. Each wheel has 4A-QPM light jet engines, saving more ASK FRED Send your questions about this article to: [email protected] also appears to make less noise than For admirers of Swiss engineering ex- are machined out of solid billets of alu- a typical APU, based upon our obser- pertise, it’s worth diving deeply into the minum alloy. Even the cursor control vations. That’s good news for airport details. device palm grip in the center console neighbors. is milled out of a solid aluminum block. “Weight control? We’re expert at it,” Structure and Systems Carbon fiber and other composites are says Schwenk. “It’s a continuous game used mainly for secondary structures, with Pilatus. It’s always about payload Walk through the Pilatus factory at particularly those with complex curves and range.” Buochs Airport (LSZC) and you’ll see such as aero fairings, the radome and The end result of the weight sav- a wholesale transformation in the way wheel well liners. ing campaign? While the aircraft has the small Swiss firm builds its first jet Wing aerodynamics proved espe- gained nearly 1,000 lb. from Pilatus’ ini- compared to its older prop airplanes. cially challenging because engineers tial estimates for BCA’s 2018 Purchase The PC-24 was designed from the out- were targeting cruise speeds as fast as Planning Handbook, a typically outfit- set to take full advantage of computer 440 KTAS and landing speeds of 100 ted PC-24 still weighs about 1,000 lb. controlled, high-speed milling processes KIAS or less. Pilatus developed its own less than a Citation XLS+. The aircraft, and robotic assembly. Skilled Swiss air- airfoil, one with a cranked-arrow lead- though, is typically Swiss tough in spite craft factory labor is expensive, so the ing edge with mild sweep outboard and of its light empty weight. It has a 30,000- new model is being built with fewer la- considerable sweep inboard. The trail- hr. basic design life, exceeded only in its bor hours than any Pilatus model in cur- ing edge is nearly straight, providing an price range by Embraer’s Phenom 300. rent production. And robots will do even unimpeded path for cargo vehicles or As with the PC-12, Pilatus already is ey- more of the assembly work in the future. ambulances to the cargo door. ing service life extension programs that As with most of Pilatus’ previous Airflow over the wing becomes will enable the PC-24 to fly well beyond models, the PC-24 primarily is an alu- mildly transonic above Mach 0.7. Sig- the 30,000-hr. milestone. minum alloy, semi-monocoque structure nificant drag divergence only occurs At face value, the PC-24 seems to be a constructed of stressed skins and inte- above the aircraft’s 0.74 Mmo, so the simple but solid Swiss product. Yet, sim- gral substructure. Cervia doesn’t like aircraft can cruise efficiently at Mach ilar to a Patek Phillippe Nautilus, there’s to use castings or forgings for compo- 0.72 or higher. As shown on the ac- an impressive array of technologies un- nents. As a result, most complex metal companying Specific Range chart on derneath the surface that makes pos- parts including wing spars, landing page 36, there’s a 7.5% spread between sible consistent, precision performance. gear struts and nose gear bulkheads Mach 0.65 best range and Mach 0.74 The PC-24 is in the stages of certification for unimproved runway operations. Pilot Report best speed cruise profiles. the anti-skid wheel brakes, probe and compartment. Battery 2 is in a com- The wing is built in left and right windshield heat. Fuel boost pumps and partment aft of the right wing. During halves with forward and aft single- the pressurization system use electric normal operation with both engines run- piece, machined spars, plus a short sub- power. Electric brakes may be used ning, Battery 1 is connected to the left spar for the aft attach point of the main on future aircraft if the price becomes generator and main bus while Battery landing gear. It’s a conventional ladder more attractive. 2 is tied to the right generator and main box design using chordwise ribs and The PC-24 is the first production bus. Bus tie relays connect normally shot-peen formed skins attached with business aircraft to use brushless AC split buses together when connected to mechanical fasteners to the interior sub- induction starter/generators. Astronics ground power or with only one genera- structure. Left and right halves are at- Corp. attempted to perfect the system 15 tor operating. tached in the center by several tension years ago with the intention of introduc- The 6,000-lb. capacity fuel system bolts to form a single piece. The wing ing it on the Eclipse 500, but the tech- has mirror-image left and right wet- attaches to the fuselage pairs of forward nology wasn’t ready. Now, it’s making wing tanks. Each tank may be refueled and aft fittings, plus a forward spigot its debut on the Pilatus jet. Each engine through an over-wing port.