AIN Special Reports

Pilot Report: Piper PA-46 M500

 - October 17, 2015, 8:15 AM
New upgrades put the focus on safety.

The PA-46 M500 refines Piper’s pitch to well heeled, value-conscious general aviation pilots considering the transition from piston to turboprop, making its upsell not with increased power and performance but with enhanced safety. It’s the definitive answer to concerns safety experts, insurance companies and pilots raise about the challenges of stepping up to higher performance aircraft, questions the original PA-46 helped crystallize.

Piper’s pressurized, piston-powered PA-46 Malibu, introduced in 1982, created the modern cabin-class single, a category now dominated by turboprops, with Daher, Pilatus and Cessna offering interpretations of the concept. Meanwhile, Piper built out its PA-46 “M-Class” line, upgrading the Malibu into the Mirage and flanking it with the flagship Meridian–certified in 2000, which brought the Vero Beach, Fla.-based manufacturer into the single-engine turboprop echelon–and the entry-level, non-pressurized Matrix recip.

Earlier this year Piper revamped and rebranded the turboprop Meridian as the M500 and the Mirage as the M350, and also announced the M600, a more powerful version of the M500, expected to receive certification by year-end.

The successful growth of the PA-46 product line stands in contrast to its entry into service. In its first iteration, powered by a 310-hp Continental, a series of in-flight break-ups and other accidents prompted the FAA to issue an AD removing the PA-46 Malibu’s certification for flight into known weather, before the agency withdrew the directive after further testing of the design. The break-ups were attributed largely to pilot error, and subsequent PA-46 models demonstrated no such accident proclivity. The new upgrades aim to move loss-of-control accidents into the realm of impossibility.

The M500’s primary enhancement is electronic stability protection (ESP), incorporated into the Garmin G1000 autopilot flight control system. (The M350 also incorporates ESP, as will the M600.) ESP–operative whenever the autopilot isn’t engaged, and augmented by underspeed protection (USP) and overspeed protection–acts like an invisible copilot, ready to intervene any time the aircraft approaches the edges of its normal airspeed or bank angle envelopes. The M500 also has a coupled go-around and automatic level mode among its list of safety features.

Piper distributor Columbia Air Service, at Connecticut’s Groton-New London Airport invited AIN to fly the M500 (and the M350) and see the results of the upgrade. Columbia’s experience with Piper turboprops predates the PA-46 era; it was heavily involved in the Piper Cheyenne aftermarket before becoming a Piper dealer in the mid-1990s. Soon after, Columbia recruited Gordon Ramsay, a Hartford native who’s been buying, rebuilding and selling airplanes since he was a teen, to serve as Piper program manager.

 The M500 Outside and In

Sitting relatively high off the ground, its long wings uncluttered by engine cowls, the PA-46 has always had a sleek, eye-grabbing ramp presence, and the small, horn-like exhaust stacks poking from the cowl of turbine-powered PA-46s add a brawny swagger to its visual appeal. Externally, the M500 and the Meridian are identical, distinguishable from piston-powered PA-46s by the extensions at the leading edge of the wing roots (for more fuel capacity); the 37-percent larger empennage; and vortex generators on the wings. There’s no nose baggage compartment, either, as the cowl is occupied by the M500’s Pratt & Whitney Canada PT6A-42A, flat rated to 500 shp.

Piper has been refreshing the interiors of the M-Class in recent years while also striving to differentiate them. All PA-46 models formerly shared the same basic interiors. Now Piper’s cabin appointments reflect the model’s position in the fleet, putting the M500 at the apex of its interior styling efforts. Its standard Premier Elegance color-coordinated leather seats, carpet and headliner are offered in two neutral-tone color schemes: Dune or Glacier. Meanwhile, new PA-46 cabins all benefit from work done by Boston’s Blokx Design, which Piper engaged to rethink and redesign cabin elements such as armrests, cup holders and stowable table, without changing production tooling. USB charging ports in the cabin and cockpit have been added to the M500.

The M500 offers a GSR-56 global satellite datalink Iridium satellite transceiver. Piper added the option with an eye on the international market, as a conduit for getting in-flight weather in areas without access to XM weather or similar services. It has found 90 percent of all buyers want the system, primarily for telephone and text communication.

The enhanced cabins dovetail with changing ownership demographics. Whereas previously about 90 percent of PA-46s were owner flown, today the figure is about 80 percent, the remainder flown by professional pilots with the owner riding in the back.

Getting into the cockpit is still a bit of a squeeze, eased by the fold-down captain and copilot’s seats, but once seated in front there’s ample room, and the uncluttered panel adds to the feeling of spaciousness. The Garmin G1000 flight deck is dominated by the two 10.4-inch primary flight displays (PFDs) and center-mounted 12.4-inch multifunction display (MFD). An Aspen EFD1000 standby instrument has replaced electromechanical backup gauges and wet compass, unifying the appearance of the panel and, more important, easing pilot workload in the event backup instruments are needed, as the data presentation basically mirrors what’s on the Garmin screens. Switches for electrical, engine start, lights, ice protection and other systems are on a pair of overhead panels, separated by a smaller control panel for cockpit lighting. The GCU 476 keypad on the pedestal simplifies entering flight plans and other data into the G1000.

Meanwhile, the landing gear safety lights now appear on the MFD instead of cluttering the panel with a dedicated display, and in another upgrade, system aural alerts and the stall horn are now audible through the headsets. The intercom has 3-D audio.

 Engine Operation and Management

The greatest challenge in transitioning from piston to turbine is operating and managing the engine, and Piper has put lots of effort into making the M500’s turbine operations simple. There’s no prop lever on the pedestal. Once the engine spools up, it turns the prop at 2,000 rpm at all times, leaving only the throttle to control the power. Also, the condition lever is simply a two-position fuel control, either in the on or off position. Other turboprop installations typically require fine-tuning the idle setting with the condition lever on the ground, to meet changing demands for powering onboard equipment. The M500’s ground idle–a minimum of 63 percent NG–provides sufficient power in all situations. The fuel system is also a simple on-off design. Automatic crossfeed keeps the wing tanks in balance. In the event of an imbalance, a fuel pump automatically engages, raising fuel pressure on the overloaded side and accelerating its fuel feed, until the imbalance is corrected.

The manual bleed-air system requires more attention than an automatic or electrically operated design, but it keeps the aircraft’s systems simple. Bleed air is kept off during engine start to ensure all the air is used for cooling the engine, rather than diverted to run other systems.

The M500’s autostart function simplifies the engine start, among the most intimidating parts of the turbine transition. After the G1000 completes its self-test, the fuel pumps and igniter switches are set to manual from the pilot’s overhead panel and autostart is engaged, which starts the engine spooling. At 13 percent NG the igniters fire, and the ITT and NG both climb. At 56 percent NG the starter automatically engages. Turn the fuel pumps to auto, and turn off the igniter. The engine is now started. Activate the generator, alternator, avionics, cabin pressurization and bleed air. The M500 is now ready to fly.

Before-takeoff checklist items include the overspeed governor, to ensure it limits prop speed to less than 1900 rpm, and reverse lockout, which prevents the engine from going into beta range in the air.

Our destination was Westchester County Airport (HPN), a mere 76 nm west. ATIS reported the wind as 250 at 12 with gusts to 16, and a scattered deck at 4,500 feet. With the tanks half full and the two of us on board we had room for about another 450 pounds of payload before hitting our 5,092-pound mtow.

 Flying the M500

Engaging the flight director and following the command bars on takeoff yields a 125-knot climb-out once the gear and flaps are retracted, and we ascended at 1,700 to 1,800 fpm. A 145-knot climb-out delivers about 1,100 fpm. The pilot advances the throttle manually during the climb to keep power between 1,250 and the maximum allowed 1,300 pounds of torque.

Ramsey describes the M500 as a “point and go” airplane: simply pick a hole in a scattered or broken deck, point the nose at it, and blast through cloud layers piston-powered aircraft would have to pick their way around to climb above.

Leveling at 15,500 feet, we reduced power to 1,140 pounds of torque and TAS crept up to 232 knots, with a fuel burn of 290 pounds per hour (just under 40 gallons). If you’re going to own and fly this airplane, this is about as low as you’d want to flight plan, so you can take advantage of the fuel savings and airspeed gains that come with altitude. Headwinds are rarely strong enough to negate the speed and fuel burn obtainable at altitude.

We didn’t need to get into the high 20s for our brief flight to HPN (service ceiling is 30,000 feet, where fuel burn in cruise is about 37 gph/248 pph), or to check the M500’s top cruise speed of 260 knots. (The M500 and Meridian have identical performance numbers; last year in a flight in a new Meridian at FL240 at -20 degrees C and some 350 pounds below mtow, I saw 264 ktas in cruise.) Range-wise, the M500’s 170-gallon fuel capacity can take it 1,000 nm with IFR reserves at economy cruise, but at normal power settings the range is about 750 nm.

Enhanced Protection Capabilities

We tried out the ESP as well as the other protection modes on a flight in an M350 immediately before flying the M500; the systems operate identically in both aircraft. ESP provides a “resistive force to the pilot deviating from nominal flight attitudes,” as Piper engineering test pilot John Kronsnoble explained in a subsequent debrief, likening it to a “flight instructor, to make you know you’re flying the wrong way.”

Piper isn’t the only OEM offering stability protection through a Garmin (or other) interface. It’s available on the King Air 200, the Cirrus SR-22 beginning with this year’s model, and experimental aircraft outfitted with Garmin G3X glass cockpits. But each OEM tweaks the system for its own aircraft. Piper’s ESP engages at 45 degrees bank, and the resistive force reaches its maximum at 60 degrees, disengaging when the aircraft is returned to 30 or less degrees of bank. The pilot can manually override the system by overpowering the resistive force, and the ESP, USP and overspeed protection can also be disconnected–during training, for example–through the Garmin Aux page. But as the default mode, full protection will be restored whenever the Garmin boots up.

USP engages when pitch attitude reaches 17 degrees nose up, with forward pressure increasing to its maximum at 21 degrees pitch up, and disengages when upward pitch drops to 14 degrees positive. In extreme high-pitch attitudes, USP disengages at 50 degrees nose up.

The addition of USP to the safety package enabled Piper to add coupled go-around to the M500, allowing pilots to fly a missed approach without disengaging the autopilot. Should the pilot forget to add power, rather than follow the command bars up into a stall the USP will override the autopilot and lower the nose, giving the pilot a chance to take corrective action.

Overspeed protection engages at 189 kias or minus 15 degrees, reaching maximum resistance at 196 knots or 21 degrees nose down, and disengaging when airspeed slows to 188 kias or pitch is shallowed to 12 degrees negative or less.

In the real world, or the skies over Connecticut in our case, this works out well. Normal maneuvers are unencumbered, but as the bank increases into steep territory, or the nose is pulled up or pushed down beyond what you’d use for normal operations, the force serves as a reminder and assistant. In addition to its corrective forces, the system provides aural alerts and visual caution warnings on the PFD when activated.

The M500 also has an automatic level mode, activated by a blue button–a panic button, if you will–in the center of the panel. When pressed, it engages the flight director and autopilot and restores the aircraft to straight-and-level flight.

Together, all these safety enhancements add peace of mind, confidence and a sense of lightened workload, particularly in single-pilot operations.

But there’s an additional concern facing transitioning pilots: the threat of hypoxia, which is believed to have had a role in several recent fatal accidents involving high-performance singles. The M500’s hypoxia recognition system provides alerts should the cabin altitude climb above 14,900 feet when the autopilot is engaged. However, Piper elected not to incorporate in the M500 the automatic descent mode (ADM) featured in the M350. When activated automatically by lack of pilot response to hypoxia warnings, ADM brings the aircraft down to an altitude at which the pilot can recover. But since the M500 cruises near its Vmo of 188 knots, engineers determined that quickly descending to a breathable altitude at cruise power could easily exceed the aircraft’s maneuvering speed, and Piper ultimately decided ADM is impractical in the M500. ADM will be incorporated into the M600, which will have a higher Vmo than the M500, thanks to its stronger wings.

Meanwhile, the Garmin integrated pressurization system simplifies regulating cabin altitude. Turn it on before takeoff and tell it the elevation of your destination airport, and the system pressurizes and depressurizes en route automatically.

Additional onboard systems further bolster safety margins for handling weather and traffic. The Garmin GWX 68 digital color radar augments the XM WX Satellite Weather services available through the optional GDL 69A, and an optional GTS 825 traffic advisory system coupled with the GTX 33ES provides ADS-B in and out functionality.

Flight into known ice capability, air conditioning and yaw damper are standard.

 Operating in Real-world Conditions

While the M500 represents a step up for most buyers, it puts them in the company of many higher performing business aircraft. Twelve nm northwest of New Haven, we checked in with New York Approach and requested the Rnav 34 approach into our destination, to see the M500 fly a coupled approach. We wouldn’t know if we’d get the approach for a couple of controllers down the road–it was a sunny afternoon in the busy Northeast corridor–but we were given a squawk code and directed to descend to 3,500 feet.

Pulling back the power to 345 pounds of torque produced a 1,450-fpm descent at 225 knots. Reducing to 60 pounds of torque steepened the descent initially to 2,700 fpm and then to 3,200 fpm. For an emergency descent, drop the gear, pull the power and point the nose down, keeping the airspeed at its 168-knot indicated maximum gear speed. With the four-blade prop acting as a speed brake, the M500 can descend at 6,000 fpm.

The wind at HPN was from 290 at 7, gusting to 17. A couple of controllers later, on a seven-mile right base along the shoreline, we were told to expect the Rnav 34 approach, and keep our best forward speed for jet traffic seven miles behind. It was the type of scenario that tests whether airplane and pilot are ready for prime time. Could the M500, known for its piston-like pattern speeds, fly fast enough down low to keep the Challenger comfortably behind us, and how easily could a transitioning pilot handle the demands of the slam dunk arrival in a high-traffic environment and blustery crosswinds?

We had no problem maintaining 155 knots, and after capturing the glideslope and starting down, we disengaged the autopilot to hand fly final. As for crosswinds, the big empennage makes landings in turbine-powered PA-46s exceptionally smooth. With power reductions and the flaps deployed, and the gear extended over the final approach fix, we had slowed to 95 on short final. That’s a little hot for standard M500 operations, but whatever the approach speed, with a landing roll of 1,020 feet, there’s rarely need for using reverse thrust, another way the M500 keeps things simple. But having jet traffic behind us altered the equation. As soon as all three wheels were down, we put the throttle into reverse and were able to exit the active at Hotel, the second turnoff, leaving the runway clear for the Challenger. That’s the kind of flying that says a transitioning pilot has arrived. With a standard equipped price of $2.264 million, the M500 can get them there with simplicity and economy.

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AIN 2015 New Turboprops (19K)

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