Dave Higdon/augusta, kansas
Mooneys's Encore climbs, descends and cruises like its hot-rod predecessor, but is a machine for serious business flying.
What most sticks in mind about one aeroplane or another? Is it handling, harmony, speed, stability or comfort? After flying Mooney Aircraft's Encore, what most sticks in mind is how it made my ears pop.
The Encore is a revival of the 1980s Mooney 252, a four seat, 165kW (220hp) turbocharged piston single that climbs and descends with equal aplomb and cruises at impressive speeds. Flight International was able to judge the success of this renaissance thanks to western region sales manager Rick Pitner.
My ears popped frequently and insistently, both going up and coming down. In a 110kt cruise-climb, the Encore ascended more than 16,000ft (4,900m) in just 16min. Using the standard-equipment speedbrakes brought descent rates that would make a rock seem competitive in glide. In the cruise, the turbocharged Teledyne Continental TSIO-360-SB accelerated the Encore to nearly 200kt (370km/h).
The Encore gives away nothing in overall efficiency to its predecessor, delivering these numbers at miserly fuel flows in the 50 litre/h range. About the worst that might be said about the aircraft is that it is actually a few knots slower than the 252.
Beyond that largely meaningless speed disparity, the Encore significantly improves on the 252 in comfort and, particularly, payload. With slightly more power that its predecessor and stronger landing gear, the Encore carries almost 100kg more than the 252, pushing full fuel payload into the 250kg range.
Mooney has also greatly improved the avionics and redundancy in the new Mooney, with digital electronics in the panel and dual alternators and vacuum pumps. The basics have not been changed, however, and the aircraft delivers solid stability and good handling, all in a package with the same one-piece wing, steel-cage cabin and aerodynamic efficiency of the 252.
UNMISTAKABLE TRAITS
When Mooney moved to Kerrville, Texas, from Wichita, Kansas, in 1953, its products already bore unmistakable traits: the welded steel-tube cabin frame sheathed in smooth formed aluminum, the stressed aluminum monocoque aft fuselage and tailcone, the trademark fin with its unswept leading edges and high speed on low horsepower.
Those traits went into the first M20s in the late 1950s and, while greatly evolved, they remain the basis for two Mooneys in 1998, the M20J Allegro (the renamed MSE/201) and the M20K Encore.
Today's M20J and M20K both use the same basic fuselage as the Mooney 201 introduced in 1977. In those days, the aircraft number reflected its speed; the 201 boasted 175kt on 150kW. The 201/M20J was refined further to produce the 205 and two turbocharged models, the 231 and 252, both now designated M20Ks.
These models all share the same laminar flow wing, one piece belly pan, fully enclosed landing gear, gap seals on all control surfaces, and push rod control linkages throughout.
Refinements introduced over the past five years include an all-new interior. Single-piece composite interior panels have opened up the cabin, hardly the most spacious in its class. With the refit, taken from the stretched Ovation and TLS Bravo models, the Encore feels brighter and roomier than its predecessors. Mooney has also refined the cabin with better sound insulation, including a multilayered firewall blanket.
The Encore adopts the heavier landing gear of Mooney's Ovation and Bravo models, allowing a 105kg gross weight increase over the 252, to 1,420kg.
Mooney had already given the MSE a major panel reconfiguration that produced one of the industry's best organised cockpits. My expectations were for a cluttered, confusing panel, but that proved not to be the case, given the location of engine instruments across the top of the panel, above the flight instruments, and the arrangement of circuit breakers on the right panel and all light switches on an overhead panel.
Packaged together, the Encore's comfortable interior, powerful avionics and abundant horsepower leave no doubt that this aircraft is built to be fast, efficient and capable. The equipped price is about $390,000.
SPEED WITH SIMPLICITY
Even on the ramp, the Encore reeks speed - from its raked rudder and swept trailing edge elevator, forward past the long, thin, tapered wing, and beyond the smooth carbonfibre composite cowling to its polished spinner. Beneath the glossy, metal flake paint finish is a mechanical simplicity that leaves nothing complicated to preflight.
The two toughest parts are checking oil and sumping fuel from the two tanks that combine to provide the Encore's 295 litre fuel capacity. Engine oil is checked through a tight hatch atop the composite cowling.
To avoid the pilot having to stoop or crawl under a wing that is only about 0.5m off the ground, to sump fuel, Mooney's engineers adapted the folding tow bar with a clever little device for holding a sampling cup in one end - put the cup in the holder, stick the cup into each fuel tank's low point drain, and press upward.
More checks await in the cockpit. The approach-certified AlliedSignal Bendix/King KLN89B global positioning conducts its own self test when powered up, as do the KFC150 flight director, the annunciator panel, the Shadin fuel management system, and even the BFGoodrich WX1000 Stormscope.
My checks included fuel gauges, both the electronically driven pair in the panel and the two direct reading mechanical analogue gauges mounted in each wing.
A little stab at the electric fuel boost pump to bring up pressure, turn the key and push, and the six cylinder Continental came to life and settled into a pleasant sounding rumble.
Up front, the same McCauley constant speed propeller used on the 252 bites at the air - Mooney tested four other propellers from three manufacturers before finding the best performance from the tried and tested 252 model.
Inside, the optional Bose active noise reduction headset reduces apparent cabin noise to nearly nothing. The option includes a power supply wired into the panel for the headsets.
It was time for me to taxi the Encore to the departure end of Augusta's Runway 36. Flaps set at 15í, brakes on, propeller, throttle and mix full in, and the turbocharger boost shot up to its maximum 990mm before the engine reached its 2,600RPM redline. The Encore surged up the inclined runway, eager to reach flying speed.
Full right rudder trim on the electronic yaw damper system eliminated any heavy load on my right foot as the Encore tracked straight along the runway centerline. At about the 1,400ft mark the aircraft cleared the runway in something more like a lift off than a rotation.
CRUISING INSTINCTIVELY
Turning right from our 360í take-off heading towards Oklahoma at a 145í heading, I instinctively selected a cruise configuration of 2,500RPM, about 890mm of manifold pressure, and trimmed to about 112kt. Pitner had wanted me to climb to 17,500ft at a maximum-rate setting, which starts at about 1,500ft/min (7.62m/s) and by 5,000ft remains at 1,100ft/min. At my settings the Encore ascended about 16,170ft in 16min. In that time we had crossed the Oklahoma border, about 85km away on our heading, and consumed about 26 litres of fuel.
At Pitner's preferred power and speed settings, the Encore would have made the climb in about 12min, covering about 55km, and consuming about 19 litres.
Throughout our climb, the moving map displayed on the KLN89B kept us appraised of our relative location. Once up where my ears popped no more, Pitner gave me a setting for 75% power, about 2,300RPM and 762mm of manifold pressure.
Hand flying proved less finicky than expected. In fact, the faster the Encore travelled, the more stable it seemed to become. Trimming for a level attitude was no problem, even at this high altitude. Pitner says that the Encore remains stable up to its maximum certificated operating altitude of 25,000ft.
The Encore would later show off admirable manoeuvrability, neither stiff nor hard to handle. Complementing this was control harmony and stability in banks up to 30í that rivalled the industry benchmark, Raytheon Aircraft's Beech A36 Bonanza. Roll to the desire bank angle, nudge the trim slightly, and the Encore happily carves flat, altitude stable turns.
By the time the Encore let me settle it into a groove, we were at 198kt true airspeed. Leaning the engine to its peak turbine inlet temperature of 900íC produced a fuel consumption of 48 litres/h. Pitner recommended enriching the mixture by 3.79litres/h to keep the turbocharger cooler by dropping inlet temperature by about 65íC. The range penalty is about 180km.
The TSIO-360-SB can provide 100% power up to 20,000ft - the engine's so-called critical altitude - and the pilot can can go faster by simply flying higher. At 22,000ft, the Encore can deliver 213kt for about the same 52litres/h used lower down. That 15kt increase more than offsets the range penalty brought by the higher fuel flow setting.
BUILT-IN OXYGEN
To use these high altitudes generally requires either oxygen or pressurisation. Mooney opted for a built-in four-place oxygen system. An integral Kevlar bottle with 3.3m3 capacity supplies all four seats through neat couplers, two in the overhead console for the front seat occupants, one on each sidewall for the backseaters.
Encore buyers have the option of regular masks or more efficient Oxymizer canulas. We used the Oxymizers, which worked well. The flow meters are easy to use. Just set the flow for the altitude and forget it.
Matching Bendix/King KX155 and KX165 radios gave us clear, crisp communications, plus reliable navigation. The KFC150 autopilot rivals those found on many business turbines, with links to the navigation receivers, plus climb and descent control and altitude hold.
Electric motors drive practically every item not linked directly to the yoke or rudder pedals: trim, flaps, landing gear and cowl flap - even the ventilation system benefits from a blower fan. Redundancy is provided by dual alternators and dual vacuum pumps.
Couple the Encore's 284litres of useable fuel with the aircraft's altitude and power flexibility, and you get an aircraft capable of carrying four adults and luggage for 1,100km, or two adults and luggage for 1,800-2,000km.
On the arrival end of the trip, when coming down and slowing down are often in conflict, Mooney's decision to standardise Precise Flight's speedbrakes pays off.
A red button on the left side of the pilot's yoke deploys the brakes and an annunciator light informs the pilot they are out. Punch the button at any speed or configuration, up to the Vne of 196kt indicated, and the Encore starts down. No trim or power-setting changes are required. Keep the power levers set and the Encore drops at about 1,500ft/min, at the cruise airspeed.
Reduce power and descent rate increases. Punch the red button again and the brakes fold back into the wing, which allows the Encore to transition smoothly back to its zero-sink trimmed airspeed.
Once slowed - gear and flap limits are more generous than on earlier Mooneys - the Encore can be flown through the pattern with aplomb. I could find no evidence of the Mooney's supposedly quirky landing characteristics in three touchdowns, all but one slow enough to make a turnoff 640m down the runway. Forget flaring on landing; it invites a float down the runway, particularly if you are a few knots too fast.
DEMANDING CAPABILTY
There is a downside to all this capability - considerable demands on the pilot. The Encore provides its capabilities because of its complement of equipment, all of which requires study, practice and use. Mooney provides purchasers with a week of training at FlightSafety International in San Antonio, Texas, which includes high altitude flight and physiology, to go with the Encore's high flying ways.
The powerful engine imposes its own demands. For example, on descents it is important to bring back power gradually, about 25mm of manifold pressure each 1,000ft. After touchdown, the handbook demands a 5min idle while the turbocharger cools down.
Nothing in the price or horsepower range delivers more in speed, fuel efficiency or range than the Encore. The entry fee can be relatively reasonable: about $329,000 for the base Encore. Our aircraft, with optional avionics and leather interior, came in at about $389,000.
The only piston singles with comparable speed are Raytheon's turbocharged B36TC Bonanza and the New Piper Aircraft Malibu Mirage, the former about 50% more expensive than the Encore, the latter 100% more. Both are six seaters with 220kW plus engines and commensurate fuel consumption levels.
Only the Mirage is certificated for flight into known icing but, around April, Mooney expects to win US approval for the TKS anti-ice system on the Encore. This will position the Encore uniquely in the general aviation market as the smallest, least expensive aircraft available for all-weather flying, and secure the place Mooney has enjoyed in the four seat market for decades - as the only game in town if speed and efficiency are priorities.
Pushrods are used for all flight controls - ailerons, elevators and even rudder
The multilayer firewall blanket sandwiches noise dampening materials with heat reflective foil to cut both heat and noise in the cockpit
De-icing fluid flows through perforated titanium wing leading edges on the TKS equipped aircraft
The shaped wingtips not only reduce drag and improve roll control, they also provide a sleek home for the wingtip mounted light clusters
Source: Flight International
