Legacy Aviation Muscle Coupe
This great-looking scale aircraft is a blast to fly
Extreme Flight RC is well known in the 3D aerobatics world for light, well-made models capable of the most extreme aerobatic maneuvers. For scale enthusiasts, its Legacy Aviation brand offers a range of civilian general aviation and vintage models. At eWeek last year, I watched a new Legacy Aviation model fly. It looked an awful lot like a Monocoupe 90 to me, and I really liked the sedate, graceful way it flew. Designed for relaxing sport flying, it’s called the “Muscle Coupe,” and I picked one up at The Toledo Show earlier this year. I also got one of the recommended Torque Revolution motors since I’ve had good service from the same motor in the Bushmaster, and I knew it would provide plenty of power for the lighter Muscle Coupe. I don’t often fly from water, so I passed on the optional fiberglass floats, but I can say they’re beautifully made and quick and easy to install.
As I unloaded the well-packed box, I couldn’t help but notice how nicely the parts were covered. On every piece, the covering was tight and unwrinkled, and the stripes and graphics were perfectly applied. As I unpacked the parts, I ran a covering iron over all the seams and stripes just to make sure they were well sealed. I then took a bottle of thin CA and went over all the wood joints I could reach, especially those in the motor box and forward fuselage.
Assembly starts with the wings, and there are no surprises in the process. Fiberglass control horns are inserted into slots using medium CA and then the flaps and ailerons are hinged with CA hinges. Servo installation is straightforward, following the directions in the manual. I used Hitec HS-7245MH servos all around, for a total of six servos. I found the anodized aluminum servo arms that came with the servos to be perfect for all the control surfaces. The kit-provided ball-link control rods are great, making a strong and tight control linkage.
Fuselage assembly follows, and again, there are no surprises. The landing gear and cover fit perfectly, and the wheel pants are easy to install. I liked the way the tail was designed, with the horizontal stabilizer slipping tightly into a slot and the fuselage recessed around the stab for a clean joint. Both parts are made of balsa wood, and the parts fit was tight enough that thin CA wicked in for a strong bond. The vertical stab is supported by two carbon-fiber tubes and also fits into a recessed notch. The elevator servo installs just like the wing servos and is mounted right under the stabilizer. The rudder servo mounts in the forward fuselage under the windshield hatch, with a long pushrod to the rear.
The recommended Torque Revolution motor mounts to the motor box easily using the supplied radial mount, and is perfectly spaced for easy installation of the fiberglass cowl. I used a Castle Creations Edge 100 speed control, and there’s plenty of room for mounting it under the battery tray with cable ties. I installed the cowl according to the instructions and then bolted
on a Xoar 16x7 propeller, painted white with red trim to match the Coupe’s color scheme.
I did the assembly over the course of a couple of evenings, and it took about three hours all told. Setting up and programming the Spektrum AR9350 receiver was fast and easy, and the plane balanced easily at the recommended spot by simply moving the power battery.
IN THE AIR
With temperatures in the high 70s and a light wind almost directly down the runway, it was a perfect day for flying. After assembling the plane, I rechecked the balance and controlsurface movement, and with it all in the “go” range, I took the Muscle Coupe out to the runway.
The takeoff run was straight, with a touch of rudder required as the tail came up. In a surprisingly short time, the plane was off the ground and climbing fast. When I reduced throttle a bit and started an aileron turn to the left, I was immediately reminded of the line in the manual that states, “Just like the full-scale aircraft, coordinated rudder/aileron turns are suggested.” Truer words were never written. With rudder input, turns are as smooth and coordinated as they should be; without rudder, they’re just ungainly and ugly. In fact, it’s easier to turn the Muscle Coupe with rudder only than it is with aileron only.
Once I came to grips with that, the plane became a lot of fun to fly. It’s capable of doing any conventional aerobatic maneuver, and the abundant power makes for big loops and nearly unlimited uplines. With the suggested control throws, the roll rate is respectable but not fast. It’s possible to mix the flaps and ailerons to make full-span ailerons and increase the roll rate, but I prefer the more scale-looking, slower roll. After the aerobatics tests, I slowed the plane and switched in half flaps, which caused the nose to raise a bit. Full flaps caused quite a bit more, so after the first flight, I mixed in a few percent of downelevator to compensate. After about 10 flights to date, 6% down-elevator with full flaps feels about right to me. Having flown the same power system extensively in the Turbo Bushmaster, I set the DX9 flight timer to six minutes, shooting for a storage-level charge after the flight. As the voice alarm sounded, I was in the downwind leg of the pattern, so I called for a landing and set up no flaps and about 1/4 throttle after turning to base and the Muscle Coupe was in a nice descent. I let it settle in, keeping it aligned with the runway using the rudder. When the plane was about a foot off the ground, I cut the throttle and the plane settled in to a smooth landing. Back in the pits, a battery check showed 3.9 volts per cell, so I knew I could add at least a minute to the flight timer.
GENERAL FLIGHT PERFORMANCE
Stability: The Muscle Coupe is fairly stable but not so much that aerobatics are compromised. If you put it in a bank, it wants to stay there until the pilot levels it out. Tracking: Ground tracking is solid. Takeoff runs require the usual tail-dragger rudder corrections to maintain heading. In the air, the Muscle Coupe is an honest flier, not changing attitude or direction unless commanded. Aerobatics: The Muscle Coupe is a fun aerobatic plane. It’s capable of all the scale aerobatic maneuvers, and big, tall loops that seem to go on forever are a lot of fun. The roll rate is fast enough to be comfortable but not too quick. The manual’s suggested elevator throws are perfect; any more would create stall issues. Spins are easy and can be flattened nicely, and recovery is easy and happens in about half a turn. Glide and stall performance: Power-off glides are fine, if a little steep. I keep some power on when on a final approach to landing, pulling it off when over the threshold. Stalls are predictable and straight ahead if the wings are level, with no surprises. Add power and keep the nose down for an easy recovery.
All the flights since that first one have confirmed my initial impressions. Aerobatic flight times of around seven minutes leave the Venom Power 6S battery at a good storage voltage. Rudder is required for smooth turns—in fact, flat turns are easy and fun to do. Pilots not comfortable flying with rudder should mix rudder to aileron and experiment to find the amount of mix that’s right.
I moved the center of gravity (CG) aft after a few flights, by moving the 6S battery back about an inch from the initial balance point. That puts the CG right around the center of the wing tube, which feels right to me.
Here the author assembles the Muscle Coupe before a flying session. Assembly is quick and easy: Two bolts secure the wing, then the two struts attach with three bolts each. (Photo by Vernon Nelson)
This photo highlights the lightweight construction of the fuselage. The firewall is reinforced with fiberglass. The Torque Revolution motor provides smooth and abundant power.
With the windshield hatch cover removed, the large battery compartment gives easy, comfortable access for changing the Venom Power battery and for accessing the receiver and rudder servo.
The tab-and-slot assembly of the stabilizer to the fuselage makes for a strong joint, with a close fit for a good, thin CA glue joint. The balsa recesses in the fuselage fit the stab perfectly, making an almost invisible junction between the parts.
Except for the rudder servo in the cabin, all the Hitec servos are mounted externally. With 7.4V radio power, they’re strong and fast, and the balllink control rods that came with the model are slop-free and well suited to the task.
Both of the Legacy Aviation planes the author owns came with a nicely made wing bag—a nice touch. Made out of reflective foil insulation, it’s nicely stitched together with two wing compartments and a pouch for the wing tube.