Barely a month following its certification, we were privileged to fly the Piper M600, the newest and greatest of the PA-46 turboprops in Piper’s stable. It appears that, from what we saw, fifteen years after the first Meridian was delivered, Piper has achieved the perfect formula for its personal turboprop.
If you’ve tuned in late, your first impression of the M600 is that it’s a higher-horsepower, higher-gross upgrade of the M500, originally called the Malibu Meridian. You would be right, but only partially so. There’s a lot of difference between the M500 and the M600, beginning with the Garmin G3000 avionics suite in the M600. The M500 remains in the product line, largely because, at under $2 million, it fits into a lower-cost niche that isn’t served by any other new-production pressurized turboprop.
According to Piper CEO Simon Caldecott, the four-year long development of the M600 has required 100,000 engineering hours and 1,800 flight test hours, but the effort was well worth it. The final FAA testing took 150 hours and was flown in just 18 days; certification was achieved on June 17, 2016.
Caldecott is especially proud of Piper’s ability to produce practically all of the components for its aircraft in-house, other than the engines, propellers, avionics and hardware items like switches. This gives the company better control over availability and inventory.
The FAA granted Piper a Production Certificate for the M600 on September 1, 2016. Initially, the M600 is to be built in limited numbers, as demand dictates, rather than in disruptive up-and-down cycles. The initial rate is to be about 35 units per year, with 2016 production entirely sold out when we visited with Piper in July.
Our test aircraft was N403MM, the first production airplane, spotless in its blue-and-white paint job with a stunning white interior. Piper’s craftsmanship reflects its desire to furnish top-drawer products for buyers who expect quality. During our walkaround with Piper’s Chief Pilot Bart Jones, starting at the two-piece airstair door, the biggest change noted from the M500 is the all-new wing. While span essentially remains unchanged at 43.2 feet, the M600’s flaps are longer and the ailerons are a bit shorter. The stalling speed in landing configuration easily comes in below the FAR 23-mandated 61 knots, despite the aircraft’s three-ton bulk. The new wing’s planform tapers toward the wingtip, and fuel capacity is now 260 gallons, enough to give a 6-hour endurance if filled, versus the 170 gallons available in the M500.
The hydraulically-operated landing gear is relatively simple in operation; the gear is actuated by an electric powerpack and is held up by hydraulic pressure, so emergency extension is a simple matter of releasing pressure to allow the gear to free-fall. A spring assist brings the nosegear into place. An 18 x 5.5 tire is used on the maingear, with a 6.00 x 6 nosegear tire up front. Unfaired wheel wells hold the retracted maingear, while two louvered doors cover the nosegear well.
The swing-up cowling allows inspection of both sides of the engine compartment. The PT6A-42A engine is basically the same as the M500’s powerplant, with an increased torque limit to deliver the 600 shaft horsepower. Derated from the engine’s 850-shp rating in the Beech King Air 250, there’s obviously plenty of reserve available for high-and-hot operations.
Demo pilot Bart Jones likened the M600 to “half of a B250”, in its payload, cabin and operating capabilities, and that’s a fair assessment. With a top speed of 274 knots and nearly 1,500 miles of maximum range, the M600 can take six people 1,000 miles. Baggage is carried behind the flat-folding rear seats, whose stowing ability can add cargo space if needed.
The engine installation is designed for simplicity and ease of operation. There are two air inlets feeding the PT6A’s aft intake screen, requiring no anti-icing on their lips, and the inertial separator is always in place, one less thing for the pilot to remember. The oil cooler inlet is below the spinner enclosing the hub for the big four-blade Hartzell propeller. The prop operates at a constant 2,000 rpm, and there’s only one idle setting on the condition lever, so the M600 is basically a single-lever airplane.
The radar pod is now mounted on the right wing’s leading edge, rather than slung under the wing as on the M500, and stylish upswept wingtips are fitted. The right aileron carries a ground-adjustable trim tab, while the rudder and elevator have actuator-adjusted tabs. The rear position light is mounted midway up on the 11-foot tall rudder. Airflow turning vanes are fitted to the aft fuselage, just above the horizontal stabilizer, to enhance rudder control. A small compartment in the left side of the aft tailcone holds preflight inspection materials, and the ground-power plug-in is found nearby as well.
A Personal Cockpit
We mounted the two-step airstair and secured the two halves of the door, which carries the 5.6 psi maximum pressure differential. The emergency exit surrounds the forward right cabin window. Sliding forward into the cockpit, access was enhanced by a slightly-lower center console, compared to the M500. Overhead switches take care of engine, lighting and anti-ice operations. There are no storm windows to ventilate the front office, so we proceeded immediately into the starting procedure. With about 1,800 pounds of people and fuel onboard, our ramp weight was approximately 5,500 pounds.
Piper’s after-start procedures are automated, insofar as switching off starter, fuel pump and ignition goes, so all we had to do was actuate the switches, hit the start button and introduce fuel as Ng rose above 13%. Start limit temp is a high 1,000 degrees, and we were soon settled into a 60% idle. The air conditioner controls are on the left side of the lower panel and the manual bleed air knob is under the left yoke.
Comfortably settled in with the prop turning, we made the acquaintance of the M600’s Garmin G3000 flight deck, a three-screen installation with dual touch-screen controllers located at lower mid-panel. The Aspen Evolution standby instruments are on the extreme left side of the panel and the usual Garmin red reversionary button was in the glareshield. There’s no annunciator panel, since all messages would appear on the central EICAS display. The array of virtual engine gauges does not include an analog propeller speed display; since there’s no pilot control of Np, only a digital readout is shown. The three gear-down lights are found in the CAS, and so are the trim-position indicators. Pressurization is scheduled through the G3000 system, which monitors the selected destination’s elevation. A manual trim wheel is retained on the pedestal, and there is an emergency manual fuel control knob next to the main power lever.
Moving away from the chocks takes little power advance, as the M600 moves easily under idle power. Piper uses a two-gate Beta and reverse selection, so taxiing is usually done with Beta control of thrust to spare the brakes. Steering control and visibility from the pilot’s seat are excellent.
Ready At The Runway
The usual Pratt overspeed governor and reverse lockout checks were made and standby-alternator function was confirmed, and we were ready to go. The M600’s torque limit is 1,575 ft/lb, so setting in a nice round 1,500 at the beginning of the roll allowed it to rise comfortably as speed increased. Lifting the nose at 80 knots had us off the ground in under 2,000 feet, using 15 degrees of flap. Flaps were retracted as 100 knots was reached, and there is a 130-knot gear retraction limit speed to be observed; Va comes at 122 knots, although 150 knots provides a more comfortable cruise-climb deck angle. At our weight, we easily exceeded 2,000 fpm in the initial climb, and could hold 1,800 fpm in cruise-climb as we passed through 10,000 feet on the way up to 15,500 feet. The M600’s ITT temps out at 800 degrees C., versus 770 in the M500.
I liked the feel of the M600’s shortened ailerons, which gave solid, big-airplane handling in climb and cruise. At approach speeds, the ailerons lighten up nicely. As we leveled off, the OAT was –4 C. and we had 1,530 pounds of torque available. The IAS worked its way up to 202 knots, resulting in a true airspeed of 250 knots on 340 pph fuel flow. At FL 250 or FL 270, fuel flows drop into the 260-250 pph range, we were told.
For descent, the M600 has a 250-knot Vmo available, so it can keep up with fast traffic more easily than the M500; Mmo is .55 up high. There is underspeed and overspeed protection built into the G3000’s architecture, as well as maneuvering restraint; when we reached 45-degrees of bank, there was a noticeable righting force applied to the yoke, and if we persisted in banking steeper the airplane rolled out into level flight. The protection can be overridden, but not easily. A “level” button can also be pushed to automatically bring the airplane back into stable straight-and-level flight.
We went to near-idle torque to check out stall handling, and found both aerodynamic warning and aural warning more than adequate. The stall break came at 75 knots IAS with flaps up and at a benign 60 knots with gear and flaps down. Again, the yoke resists intentionally being pulled back into the stall and the nose will be pushed down by the autopilot.
Returning for landing, Bart Jones showed us that 500 ft/lbs slowed the aircraft predictably to the 170-knot gear-down speed, and 15-degrees of flap could be selected at 148 knots or less. As we rolled onto base leg, I confess that I found the 112-knot full-flap limit speed a bit too confining, but 300 ft/lbs kept us moving nicely and we slowed to a comfortable 85 knots on short final. We floated for a while, feeling for the ground, but the touchdown was easy and we exited in about 3,000 feet of rollout.
Our impressions of the M600 are that it’s what Piper had in mind all along when it designed the original Meridian. It can haul a good useful load, can carry plenty of fuel when needed, and is easy to fly, manually or with automation. The simple systems make for low pilot workload. All in all, it should fill its flagship role at Piper with great success.