An impressive performer, the single-turboprop Meridian positions New Piper solidly in the business aviation market
Dave Higdon/VERO BEACH, FLORIDA
In the seven years since Piper began its post-bankruptcy transformation into New Piper Aircraft, executives have managed the company's growth and product development by incremental steps.
New products, beginning with the debut of the Seneca V in January 1997, have involved more evolution than revolution. Production numbers have climbed cautiously to last year's 400-plus mark on the basis of upgrades to Piper's time-proven Warrior, Saratoga and Malibu platforms.
Then came the launch of the Meridian and industry buzz about the company changed pitch to an audible chatter. Could Piper revise thePA-46 Malibu Mirage into a turboprop of value? Could the company pull off the engine change with the design's margins and reputation intact? And would the market embrace a Malibu priced well above $1 million?
Based on a sampling of what the PA-46-500TP Malibu Meridian delivers - as well as a glimpse at New Piper's delivery queue and 2001 billing expectations - the initial answer to each must be an unqualified "yes". Simpler to manage than the piston-powered Mirage, as fast as any turboprop single on the market, and the lowest-price pressurised turbine available, the Meridian seems all that New Piper promised.
Well-rounded
Piper's success in delivering a well-rounded aircraft stems at least partly from the changes that differentiate the turboprop- from the piston-powered Malibu from which it evolved. To an extent, the Meridian is a different airframe - rather than simply a PA-46 re-engined with a Pratt & Whitney Canada PT6. Between the advantages of the turbine engine and the complementary airframe changes, the Meridian seems close to a perfect pilot's aeroplane.
That said, there are aspects of this speedy mount that could - and likely will - be improved. Regardless of how that works out, Piper appears to have a winner on its hands - with little immediate competition in either price or utility.
The least impressive aspect of Piper's otherwise admirable PA-46 has always been its powerplant - the 230kW (310hp) Teledyne Continental used in the original Malibu was swapped in 1989 for a 260kW Textron Lycoming TSIO-550 to make the Mirage. But it seemed that designer Jim Griswald's near-perfect airframe lacked an engine to match. When PropJet, a company in Spokane, Washington, developed an supplemental type certificate to install a PT6, a small but steady stream of Malibu owners quickly lined up to make the switch. The match ofPA-46 airframe to turboprop power seemed perfect - even though the conversion's 560kW output seemed excessive to some.
New Piper appeared to echo that view when it opted for the 765kW PT6A-42A, but flat-rated it to 300kW, when it launched the Meridian (later raising the power level to 370kW). Ultimately, the company retained only the fuselage/pressure vessel as original, making changes to:
The wing: inboard cuffs improve handling, lower stall speed, increase fuel capacity and broaden weight distribution; landing gear: this has been strengthened to accommodate a higher weight;
Additionally, Piper strengthened the Malibu's wing spar in 1999 so the two aircraft could share the same structure. This change gave the Malibu a 27kg gross-weight increase. These airframe changes couple with the PT6 to make a union of engine and airframe that is close to perfect for the single-pilot market Piper is targeting with the Meridian.
Cooler look
General aviation afficionados generally recognise PT6 installations by two tell-tale traits of its back-to-front design: dual, curved exhaust stacks just aft of the propeller; and the oversize "guppy" scoop beneath the cowl that routes intake air toward the back of the engine.
The Meridian lacks that wide-open mouth. Instead Piper, working with P&WC, has created a smoother, more-aerodynamic PT6 installation using a pair of NACA scoops located at the 4 and 7 o'clock positions of the cowl. These intakes solve a number of problems, and simplify both manufacturing and operation of the Meridian by eliminating two items previously universal to PT6 installations: the inertial air separator located at the back; and a door mechanism that closed off the separator to route ram air directly into the engine intake.
Between these engine-air intakes is a third, smaller NACA inlet that routes air to the engine oil cooler. Together, these three scoops give the aircraft a sleek, svelte appearance that makes the Meridian appear longer than the Mirage. But the turboprop is only 230mm (9in) longer overall than the piston-powered PA-46. Keeping the propeller as close to the wing as possible helps improve handling and stability. To keep length close to the original Malibu, Piper has had to give up the forward luggage compartment located between the firewall and forward fuselage bulkhead in the piston versions.
Other changes - hardly noticeable - involve the cabin windows. The Meridian's 9,150m (30,000ft) service ceiling required Piper to use double-pane window fixtures, required on aircraft certified for flight above the Malibu's 7,625m ceiling.
Internally, the two aircraft appear nearly identical - save for some redesign work for the Meridian that expanded the aft luggage area to make up for the loss of the Malibu's forward compartment. Otherwise, both piston and turboprop interiors sport club seating for four aft of the flightdeck, one of which can be traded for an optional entertainment/office module.
Easy on the eye
Meggitt's flat-panel cockpit display hardware, offered as a $95,000 option, has proven so popular that no standard panels had been ordered out of more than 110 aircraft sold as of late April. Piper has yet to certify the Meridian with electromechanical instruments.
Easy to read, easy to understand and simple to operate, the Meggitt system provides primary flight displays (PFDs) for each pilot station, two screens that can serve as back-ups or show an automatic direction finder (ADF) display, and two smaller displays in the centre that present engine, air and fuel information. Each PFD is driven by its own combination solid-state air-data and attitude and heading reference system (ADAHRS). The ADAHRS for the co-pilot's screen can drive the pilot's display if that display's sensor fails, but not the reverse.
The PFD is intuitive and easy to read at first glance, as it mimics a standard attitude-indicator. Even with vertical tapes for altitude and airspeed flanking the attitude display and a bottom-of-the-screen compass rose for the directional gyro, there is nothing confusing or inconsistent that requires deciphering.
After seeing Meggitt's displays at trade shows over the past several years, their appearance in the Meridian was a little disappointing. Compared with other colour displays now available, the resolution seemed less sharp. That said, the displays worked flawlessly and are more than up to the task.
To power the avionics, the Meridian has two independent, high-output electrical systems, a 250A starter/generator and a 130A alternator. Piper has designed the systems to give each the individual capability to handle all critical systems. There is a small set of back-up instruments at the top of the centre panel. The airspeed indicator and altimeter are air driven, while the electrical attitude indicator runs off its own back-up battery, which is continuously recharged while the engine is running.
Which brings us to the only significant caution about a pilot's shut-down practices. The standby attitude indicator's independent battery can be inadvertently discharged should a pilot leave on the master switch. And the time needed to recharge that battery could leave a pilot without a back-up should the Meridian's electrical system fail early in a flight.
For many pilots moving up from a Malibu or other piston aircraft, the simplicity of managing the Meridian may come as a surprise. A fuel control lever left of the power lever is solely a manual override in the event of a problem. The condition lever to the right of the power lever goes to the run position on engine start and stays there until engine shut-down.
Single-handed
Once the engine fires up, the pilot need handle only the power lever and watch the torque dial on the Meggitt display - with no temperature limitations, the only concern is keeping the torque needle from turning red. This leaves the pilot free to manage the gear and flaps, engage the S-Tec System 55 autopilot and program the dual Garmin GNS-530 GPS satellite navigation systems or GTX-327 transponder.
The systems combine to make flying this aircraft easier and more comfortable than anything with a propeller in my experience: engage the engine-start mechanism, watch for over-temperature events and move the condition lever to run when the PT6 lights off; pull the power lever into beta range when the propeller automatically unfeathers - and wait.
The ADAHRS need three motionless minutes to initialise and reference themselves - three minutes that begin after the engine starts and main-bus voltage returns to normal, and the 180s clock on the PFD begins to count down. That leaves the pilot time to enter a flight plan, listen to automated weather, call for clearances and secure any passengers.
Planning a long-distance mission, with a full 675kg (173USgal) of Jet A fuel on board, leaves only 185kg (408lb) of payload with the standard-equipped aircraft. Add a couple of options, and there is barely enough for two people. For our flight we started out with only 445kg of fuel, leaving room for a passenger.
Engine start, ADAHRS initialisation and flight planning took five minutes. Vero Beach ground control cleared me to the runway 29L run-up area. We taxied there with the engine barely out of the beta range. Both electrical systems showed normal; the standard automatic boost pump was armed and it was time to roll.
Advancing the power lever full forward is not advisable, since the engine quickly exceeds torque limits. With an eye on the needle, my right hand edged the power lever to about 1,520Nm (1,120lbft) of torque. When the gauges settled, the brakes came off and the Meridian surged forward smoothly, accelerating quickly towards a target 80kt (150km/h) rotation speed.
With 20° of flap and a touch of nose-up pitch trim, the Meridian rotated easily in under 20s after using about 425m (1,400ft) of runway. After stowing the flaps, the gear retracted into the wells in about seven seconds, while my left hand retrimmed for 140kt and we turned right to a heading taking us out over the Atlantic.
Having flown a 230kW piston single the day before, I expected more need to correct for the turboprop's higher power on the climb; my expectation was misplaced. With 1,330Nm of torque and trimmed to 140kt, the Meridian took me from sea level to 17,500ft in under 14min - with a great view over the nose, which looked so much shorter from inside the aircraft.
According to my calculations and Piper's book numbers, Meridian pilots can expect to reach the 30,000ft service ceiling in about 26min. You can get there faster, by climbing at a view-diminishing 125kt. Piper shows a 19 min maximum-effort climb to reach 25,000ft.
Level at 17,500ft, with the cabin altitude showing 7,000ft, it was time to trim for cruise and set power for economy. With a 98kg/h (216lb/h) fuel flow, the Meridian settled in nicely at a true airspeed of more than 190kt. Up higher, running at 109kg/h, the Meridian books out at just under 240kt. Maximum cruise speed is listed as 262kt, although operators report speeds in excess of 270kt while burning near 127kg/h. Plan for 250kt and 113kg/h, and you should always arrive with a comfortable fuel reserve - about 1,800km (1,000nm) away from your starting point.
One important note: thanks to the engine's flat-rating, the Meridian maintains the capability to pull 100% power up to its certificated service ceiling. That power capability requires the pilot to keep engine torque limits in mind throughout the flight, as well as airspeed redline if cruising below 25,000ft.
Managing fuel in flight requires virtually no pilot input, thanks to the system's simple design. Gravity feeds fuel from the two wing tanks into a header tank behind the engine. An engine-driven pump then feeds the fuel from the header tank to powerplant. Should manoeuvring cause an imbalance in fuel between the two wing tanks, an automatic system will illuminate an annunciator on the panel to inform the pilot a pump has switched on in the heavier tank. The pump increases flow from that tank long for enough to correct the imbalance. Other than switching on a boost pump at engine start, the pilot need not ever touch the fuel system until engine shut-down.
Hands-on
While the S-Tec autopilot can fly the aircraft literally from wheels up to wheels down, ceding that much work to a machine denies the pilot the biggest treat: the Meridian's in-flight manners. Power aside, any pilot seasoned in operating high-performance piston singles - particularly turbocharged models - should find nothing to fret about in hand-flying the Meridian.
First, the flightdeck design better favours the single pilot than many piston models. Controls and switches align logically and are within easy reach of the solo pilot. Critical circuit breakers reside just to the left of the pilot, ranked in order of importance. Other breakers fall within reach on the opposite side of the flightdeck. Second, the aircraft's in-flight manners leave nothing to be desired. Descent management involves little more than pulling back the power lever to achieve the desired descent rate and flying the airplane as needed.
Stalls should not concern Meridian pilots. They come straight and easy, with pre-stall buffet setting in more than 10kt ahead of the actual break. Even after the onset of full stall - listed at 79kt clean and 61kt with gear and flaps extended - the nose porpoises just enough to keep the horizon in full view.
Arrival back at Vero Beach offered an exemplary example of the Meridian's confidence-building manners. After an hour-plus in the air, Vero Beach approach told me to turn southwest to intersect a left base for runway 29L. Turning to the new heading with my left hand, with my right I retarded power until the vertical speed indicator registered 1,500ft/min down.
Crossing the Atlantic shoreline at the designated check point, the Meridian was trimmed to below 168kt indicated, the maximum for lowering the gear. Extending the gear increased the descent rate to 2,000ft/min. After levelling at 3,000ft and turning northeast for the base leg, further power reductions and pitch-trim changes brought the aircraft below the maximum flap speed of 118kt indicated, and allowed stabilisation at 110kt and 500ft/min.
Unmindful of the stiff northerly wind blowing at sea level, my hands instinctively worked the controls to align the Meridian with the runway centreline. At about 800ft, we cleared as the number two for the runway when a straying Seminole ahead created some concern.
The light twin appeared to break off its approach, then crabbed back toward the runway, barely making its way to the right-hand side of the pavement. While I was considering whether to abort my approach, the Seminole touched down and headed toward a turn-off.
But after holding at 800ft and reaching about a half-mile out, we seemed to be high. An aggressive slip corrected the problem and the aircraft crossed the threshold at about 75ft as my hands and feet worked to realign it and reduce power to zero.
The Meridian locked in place, touching down left main, right main, nose gear - about as quickly as you can read this sentence. Only when we were down and flaps were stowed did my eyes spot the wind sock, shaking in the 20kt wind at 80° to the runway. The Meridian never felt beyond its maximum demonstrated crosswind capability of 17kt. In fact, concentrating on the antics of aircraft ahead kept me from even glancing at the windsock and probably saved me any worries about landing in the crosswind or considering a change to runway 4.
As good as it gets?
Overall, New Piper has exceeded expectations in design and execution of the Meridian, changing enough to make the marriage of engine and airframe as good as it gets - without creating any nasty traits or pilot-challenging procedures in the process. The Meridian exemplifies what an aircraft should provide a serious pilot with: simplicity, thoughtful design, friendly flightdeck layout, confidence-inspiring handling, great comfort and excellent fit and finish. Completion of known-icing certification - expected later this summer - will give Piper bragging rights on creating the closest thing to the perfect aircraft in my experience.
That said, a couple of small improvements would close the loop. Top of the list is a gross-weight increase that improves greatly on a rather limiting full-fuel payload. Currently, for missions under 900km, the Meridian provides all the comfort and accoutrements needed for four people and baggage. But between the niggardly 185kg full-fuel payload and the knowledge the airframe is good for more, there is the potential for Meridian pilots to launch on long trips over gross weight, knowing they will land well below maximum weight.
The Meridian helps fulfil New Piper's hopes of building a new line of business aircraft for the new century, a line that insiders hint will include new models with new engines, existing models with new engines, and new models with existing engines. Bolstered by a backlog of over 130 Meridians, Piper plans to build a total of 542 aircraft this year - its highest output since emerging from bankruptcy in 1996.
I flew PropJet's PT6-re-engined Malibu for Flight International four years ago, and again shortly after my Meridian flight. Although payload and performance are nearly identical, the Meridian's handling seemed better harmonised, possibly a result of the subtle airframe changes Piper has incorporated.
For those who can't wait for, can't afford, or are not impressed by the changes wrought in the Meridian, a converted Malibu could suffice. But for those seeking an aircraft designed with the airframe tailored to the powerplant, with cutting-edge panel systems and a higher service ceiling, the Meridian offers the only option.
Source: Flight International
