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E-flite’s Alpha 450 Sport Electric Powered Park Friendly Trainer
by Eric Henderson
In fact, one might claim that the Alpha 450 Sport is the Park Pilot version of these tested and extremely popular glow-powered Basic Trainers and one would not be far off from the truth. The covered wood construction and general outline is identical to the larger aircraft.
However, instead of the usual foam construction, 3-channel pusher Basic Trainers one usually finds in the Park environment, the Alpha 450 is a wood construction, 4-channel (has ailerons), tractor format Basic Trainer that flies just like its larger cousins. It even has a steerable nose gear.
The E-flite Alpha 450 meets all the aircraft requirements of the Academy of Model Aeronautics’ (AMA) Park Pilot Program. The aircraft weighs less than 2 pounds (the Program’s upper weight limit) and has a level top speed under 60 mph (the Program’s upper speed limit). For complete Park Pilot aircraft details, visit ParkPilot.org.
The AMA Park Pilot Program offers non-AMA members the opportunity to become AMA members at a much reduced cost. Park Pilot membership includes a great magazine “Park Pilot”, $500,000 personal liability insurance, $2.5 million liability insurance for the flying field owner (see insurance details) and membership in the world’s largest sport aviation association – the AMA. For complete information and details about Park Pilot membership, just click here.
The ARF version is reviewed in this article. The primary difference between the ARF and the PNP versions, apart from a much lower price, is that the ARF version requires all of the electric power system and the servos to be purchased separately. The PNP version needs only the 1,800 mAh, 3-cell Li-Poly battery and a receiver as the brushless motor, electronic speed controller (ESC) and all of the servos are pre-installed.
To complete this ARF version, all of the components described on the box and in the manual were used. In addition, an available DX7 2.4GHz Spektrum transmitter and AR6110 receiver were selected to guide the Alpha 450. Note that the Alpha 450 can be flown just as well using the much less expensive Spektrum DX5 or DX-6i transmitters. The airplane only needs the four primary functions of aileron, throttle, rudder and elevator.
What you see is what you get! Well…not quite! The front of the ARF box shows a completed model that still needs a part. The aluminum spinner is optional and needs to be purchased separately. (Ed. Note: The 1.75 in. aluminum spinner is available from Horizon Hobby for $18. The order number is: EFLSP175. While not required for flight, it does improve the airplane’s appearance.)
If you follow the instructions and use the recommended equipment, the “no hassle” claim on the box will prove to be correct. The side of the Alpha 450 ARF box does show all of the additional goodies that you need to complete the model. The recommended electronic completion parts are:
The other side of the Alpha 450 box shows very good details of how the airplane will finally look plus where the flight power battery goes.
The non-glossy, but very clear, assembly manual makes the “building” easy. The components selected all matched those used in the manual so there was no confusion as to what went where. The recommended completion parts were already a proven system that was both compatible and very effective. No electric-power-system guesswork here and everything fit their respective mounts!
Here is the power package. No soldering of terminals was needed. It all just mounted easily, plugged in and was ready to go. The new Spektrum AR6110 receiver with 90-degree-oriented antennae provided the communications. The E-flite S75 servos handled the control loads with ease.
The nose-leg mount bearings and the steering pushrod are pre-installed. The nose area is left open for proper air-cooling and easy access.
The fuselage center section shows the laser cut plywood construction and the ample room for the receiver, ESC, and servos. There is a lot of inside space for a Park Pilot airplane.
The tail is simply attached with three bolts that go through these three matching holes in the fuselage.
Here is a side view of the fuselage. No holes are needed for a switch as the battery and ESC connectors exit the fuselage bottom making it easy to connect or disconnect the battery without putting your hands or body in the propeller’s way.
The stabilizer is held in place with two bolts from the vertical fin and a third bolt at the rear.
The wings are structures using balsa wood and some plywood then covered in heat-shrink material; probably UltraCote™. The wings use one servo per panel for the ailerons. The wing halves are joined using a carbon-fiber tube. They can be left that way or glued. A choice you can make based upon the size of your airplane-transport/car or the storage space available at home.
The hardware collection consists of a molded main undercarriage with the wheels already fitted, a wire nose strut with wheel already mounted, a carbon spar tube/rod for the wing (very light, very strong), machine screws for wing retention, aluminum motor mount stand-offs, nose wheel steering arm, pre-formed aileron pushrods, servo arm connectors, a white plastic spinner, and a battery strap.
The Alpha 450 only requires a small Phillips-head screwdriver and a pair of scissors to cut the Velcro. No other tools or glue are required to get the airplane flight-ready. However, if you wish to epoxy the wing halves together, you will need some 5-minute epoxy but this is not required.
The first thing to do was fit the main landing gear in place on the fuselage. The Alpha 450 comes with a molded main undercarriage that is held in place with two (2) screws. The nose gear leg is fitted and hooked-up to the steering pushrod. It is easier to do this before the motor is installed. It also now lets you stand the model upright.
The brushless outrunner motor is held in place with four long bolts. These bolts are fed through aluminum tubes that position the motor forward of the fuselage sides. Not the nose gear leg mounted and the steering arm connected.
There is a large hatch under the fuselage for the Li-Poly flight battery. The hatch is retained by a super magnet. The supplied battery strap did not prevent the battery from moving back and forth. A shorter, two-sided hook and loop tape-strap was substituted and a small piece of self adhesive hook and loop fastener added to the battery to stop it from moving around in flight.
The ESC was mounted just under the wing on the side opposite the hatch.
The elevator and rudder pull/push rods are already in place, but are not connected to the servos until the vertical fin and stabilizer are bolted in place. The steering pull/push-wire is fitted to the rudder servo arm to give coordinated rudder and nose-wheel steering.
It is important to hold the brass connecter with a pair of pliers when retaining screw is being tightened. Over-enthusiastic tightening of the screw can easily bend the wire.
The vertical fin and stabilizer mount using the three bolts discussed previously. Make sure that the rudder clears the mounting bolt and is free to move.
Here you can see the servos move and how they move the control surfaces. The brushless motor is also given a short burst to check for correct wiring and rotation. You should perform this motor test before the propeller is installed. I installed the propeller for this video as it can be difficult to see on a video just the motor turning without the propeller.
The Carbon Fiber Spar, strong but very light, provides extra strength in this wing. The panels were joined with some 5-minute epoxy resin but gluing is not really necessary. The wings were constructed so well that the joint seam was hard to see after the glue had cured.
The servo leads are fed through the wing with the help of cords that were pre-installed by the manufacturer.
The two aileron servos are driven by one aileron channel. For neatness, a Y-lead extension was used to connect the wings to a single aileron extension lead. (Ed. Note: Or, if you wish, use the Spektrum transmitter’s “flaperon” setting and connect the right servo to the receiver’s aileron channel and the left aileron servo to channel 6.This allows trimming out any possible adverse yaw by adjusting the aileron differential transmitter function. However, any buddy box transmitter would then have to be a 6-channel unit.)
In a small deviation from the manual, the aileron servo arms were angled forward slightly. This gave a better roll response and also kept the nose down when entering an aileron initiated turn. Angling the servo arms slightly forward makes the ailerons move further upwards than down. This manually sets a certain amount of aileron differential helping to reduce adverse yaw.
The pre-cut aileron pushrod that comes with the ARF is just the right length to create the desired servo arm angle. The stabilizer and Vertical fin are held in place with bolts and lock nuts that have built-in nylon seals to prevent their coming loose on their own. The added advantage of these lock nuts is that you do not have to compress the wood of the fuselage to make them tight. Install them tightly but do not crush the wood. When sufficiently tight, the stabilizer and vertical fin will not move but the nuts are not imbedded into the fuselage bottom.
There is a large opening under the fuselage behind the main landing gear. This functions as a cooling-vent exit for the air that passes over the motor, battery and ESC. Note the battery and ESC hook up connectors exit the fuselage bottom and are easily reached to either plug in or to disconnect. The wing-retaining machine-screws use a supplied and pre-covered plywood plate. This plate prevents the bolts from pulling through the softer balsa wood of the wing trailing-edge.
The aileron servo extension is plugged into channel-2 using a Y-lead. The ESC servo-type wire is plugged into the throttle channel to provide receiver/servo power and throttle control. The elevator and rudder were plugged into channels 3 and 4, respectively. The receiver was then held in place with two-part self-adhesive hook and loop tape.
You need to line up of the control surfaces and set/check them for neutral. To do this, you switch on the transmitter and connect the Li-Poly battery. [BE SURE TO HAVE THE THROTTLE STICK IN THE LOW POSITION.] This might be best performed without installing the propeller.
Set all of the transmitter trim levers to their center positions and then, using the screw in the pushrod connector mounted on the servo output arm, adjust each control surface to put the flight control at a neutral (centered) position.
The entire assembly process took 2-1/2 hours. This time included taking assembly photographs.
Time to pose for the camera! The completed and now really-ready-to-fly Alpha 450. Here are a couple of side views. The airplane somehow looks sleeker than a high wing Basic Trainer is supposed to look.
Notice the family resemblance? The airplane on the left side is the Alpha 60. The Alpha 60 has a wingspan of 6 feet (72 in.)! Yet the Alpha 450, with 2 feet (48.5 in.) less, looks and flies the same as the “big one”.
Back and front views show the color contrast that will stand out well in both good and low light.
The white plastic spinner is a nice touch that stands out well in flight and makes the trainer-type nose more attractive. It also does cost less than that shinny new aluminum spinner pictured on the box.
The wing is held in place with two bolts that need to be checked before each flight. The red underside of the wing and stabilizer gives a good contrast in flight. (Ed. Note: On the Big One, the Alpha 60, I had to add a wide white stripe on the left side of the wing’s underside to aid visibility in cloudy conditions.)
A peek underneath at the control hook-up and the air vents that help cool the motor, speed controller, and the battery. The battery leads are left poking through the vent holes. This makes it easy to connect the flight battery when you are ready to fly. It also enables quick disconnection after a flight; a good safety measure. This extra connection ease allows the safe elimination of the usual radio system switch.
The new Alpha 450 in place for its first flight. Go ahead, add power and take the ride!
The Alpha 450 literally leaps into the air. Very short take-offs can be done from grass runways. Here are a series of take-off snapshots showing the Alpha 450 “frozen” in the sky just after lift-off, then turning back towards the camera.
Here are two of those obligatory One-Wing-Low passes every review is supposed to have. But they do show the airplane’s attractive colors while airborne.
What the still camera can’t show is how well the Alpha 450 holds it altitude and responds to the elevator in the turn. The videos do help in showing how well the airplane flies.
Figure-8 turns were equal in both directions.
Performing aileron rolls was a very pleasurable activity. The pilot’s confidence factor increases very quickly with this airplane.
Inverted flight is fun and needs only about 30% down elevator to hold level flight. As with all other Flat-bottom wing Basic Trainers, outside loops are extremely difficult, if not impossible, to fly. But then, inverted maneuvering is the territory of Advanced Trainers with their symmetrical airfoils.
Landings were very easy. Just line up on the landing area, reduce the power and fly the Alpha 450 down to a very slow landing. No, the Alpha 450 doesn’t land itself. It just feels like it does to the pilot.
Make sure to view the three flight videos to get an even better idea of how well this airplane flies.
The electric Alpha 450 ARF is a colorful and cool looking trainer with a semi-scale appearance. The overall flying characteristics are really great. As a Basic Trainer, the Alpha 450 is stable all the way down to very slow flying speeds. You could fly this airplane by just using rudder and elevator if you felt like it.
Several aerobatic maneuvers were tried out. Stall-turns can be done fairly easily. Rolling maneuvers were the nice surprise. They could be performed quite slowly and the nose held up with a touch of down elevator. The airplane stayed on its rolling axis most of the way through the roll, with a little dip at the end. The roll rate does speed up if corrective rudder was added as you came out of the inverted section of the roll. This is normal and to be expected with this airplane configuration high wing, generous dihedral and flat-bottom airfoil wing). Loops tracked well and were very respectable in size.
The videos were recorded with the help of New Jersey Pine Barons club members Jim Faulkner, Alex DeMayo and Joel Gilpin.
For more information about this affordable, great Park Pilot Basic Trainer ARF, go to: HorrizonHobby.com
For more about the PNP version, go to: HorrizonHobby.com
Excerpt: Movies Added! Hangar 9' successful Alpha glow-powered Basic Trainer series has been teaching new RC pilots how to get into the air for almost a decade. The new E-flite Alpha 450 Sport looks and flies as well and as easily as its big brothers but is electric powered and the right size for Park Pilot flying. Walk on the small side and try out this new airplane in the Park Pilot Section.
Post date: 2010-05-14 14:30:16
Post date GMT: 2010-05-14 18:30:16
Post modified date: 2010-07-06 09:32:10
Post modified date GMT: 2010-07-06 13:32:10
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