DH82a Tiger Moth 400
Introduction
The GWS DH82a TIGER MOTH 400 is a full-function foam R/C airplane. (GWS stands for Grand Wing Systems). By “full-function” we mean that it employs four transmitter controls to manage throttle, ailerons, elevator and rudder. It is a lightweight, electric-powered biplane model of the famous between-the-wars British primary pilot trainer.
The De Havilland Tigermoth joined the RAF Service in 1932 and served as its Primary trainer until 1952. 30 years? It must have been one great trainer. Some Tiger Moths remained in service up to 1959. Many are now highly-prized civilian aircraft while others still fulfill their original role as a trainer. However, most Tiger Moths still working as trainers are mostly used by experienced pilots getting “tail dragger” ratings.
The GWS Tiger Moth 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, follow this link.
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.
CONTENTS
Photo 1 Photo 2
The box is very colorful and shows informative pictures of the airplane. The initial question was going to be would it look as good when assembled out of the box as it looked on the box cover? There are a lot of parts to assemble but then this is a biplane and a scale biplane at that.
Photo 3 Photo 4
To complete and fly the model you will need a transmitter, a receiver, three servos, a battery pack for the motor and a speed controller. This GWS ARF comes without any radio or flight system. GWS does supply the electric motor, gearbox and the propeller.
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A CD is included that shows all of the other GWS products that you can buy.
The primary parts are all made out of expanded foam that has been molded to create an airplane. The wing, stabilizer and vertical fin are molded as one-piece items.
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The pre-molded fuselage comes in two separate halves. It differed from the instructions in that the white foam used in the instructions had already been painted yellow at the factory. The foam was light but also fairly stiff and dent resistant.
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A closer look shows the internal shaping and cut-outs for the servos, radio receiver and battery. You can also see the ducting for air to cool the Electronic Speed Control (ESC), the Battery Eliminator Circuitry (BEC) and motor battery. Notice the many broad interior surfaces that are used for gluing the halves together. The broader the gluing area, the easier it is to prevent any glue from reaching the exterior finish. The Tiger Moth should be an easy fuselage to assemble cleanly.
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The fin and rudder are molded as one piece. The stabilizer and elevators are also a one piece molding. The builder will have to cut them apart along their hinge lines.
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All of the clevises, horns and steering components are attached to a plastic “Christmas tree” for easy identification. Another “Christmas tree” is provided with all of the components that you need to fit the wheels and aileron pushrods. This clear plastic tree is not shown here because it would not photograph easily.
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The main and tail wheels are very lightweight. The undercarriage wires for both the main wheels and the tail wheel arrive already bent to the correct shape.
Photo 19
The engine cowling is made of thin black plastic and is simply attached to the fuselage with small screws. Some mold flashing will need to be cut away from the cowling’s rear section but that is not hard to do.
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The supplied motor is a GWS/FAS4-EPS400-01 brushed version. It comes pre-assembled in its own gearbox. GWS also includes a plastic propeller and spinner.
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GWS provided the glue to complete the model. The GWS glue works well with the foam, but requires you to wait until it has cured. This can take quite awhile (sometimes hours if applied thickly). The tube holds much more than you will need and can be used later for repairs. The cabane and Interplane struts (the ones that go between the outer wing panels) are made of a nylon-type plastic that seems pretty durable.
Photo 22
Both top and bottom wings are molded in one piece. As is true on the full-size Tiger Moth, only the bottom wing is fitted for ailerons. The Tiger Moth’s top wing, without ailerons, slows the roll rate to one most student pilots will find comfortable. Yet the airplane can perform reasonable aerobatics.
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The GWS foam molding process took the time and trouble to implant the look of fabric stretched out between the wing ribs. The full-size Tiger Moth had fabric covered wings and the molded foam effectively recreates that effect.
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Molded into the wings are places for a spar, servos and aileron control torque-rods. The wings need all of the supporting hardware because, like the full-size Tiger Moth, they cannot hold the weight of the airplane in flight without them.
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There are eight places on the top and bottom wings for the strut hard-points.
Photo 30
To give the TIGER MOTH 400 the look of the British full-size trainer, GWS provides a large sheet of self-adhesive decals.
Construction
The Fuselage:
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The manual is essential in putting this airplane together. Try to avoid guessing where the parts go and do try to follow their building sequence. It will pay off in the end. The photos are clear and the instructions are numbered with reference to the pictures.
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To mount a secure bolt plate into the fuselage to hold the bottom wing in pace, a nut is pre-fitted to a hard plastic plate and positioned before the two fuselage halves are joined.
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Photo 37
The pushrod tubes for the elevator and rudder control wires are also fitted before the fuselage halves are joined. The wires are removed during the gluing.
Photo 38 Photo 39
The supplied GWS glue gives you time to position the two halves accurately. The instructions mention not using strongly adhesive tape to hold the halves together while the glue dries. This is because the tape can easily pull off the paint.
For the review, rubber bands were used. In some places, they were stretched a bit too tightly and left some imprints on the fuselage corners. Instead of over stretching (Doubling) the rubber band, use two or more located next to each other. This prevents damaging the fuselage.
Photo 40
The wing bolt was left in place to keep machined threads clear of any glue. The rubber bands did a good job holding the fuselage halves together, but if they were applied too tightly, they caused an indentation in the foam. Tape would be better but it pulled the paint away from the foam. The pre-painted fuselage proved to be a bit of a mixed blessing in this area. Make sure to follow the multiple rubber band tip discussed above.
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The installation of the motor was very easy. One screw to hold the gearbox/motor in place and the GWS glue attaches the motor beam to the foam. The wooden beam system tends to break first in a hard crash and helps protect the motor shaft from getting bent. The speed controller used was from a ZAGI that I had lying around. It was solder connected to the motor first and then slid into the channel that leads to the inside of the wing bay as the motor beam was glued into place.
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A small amount of foam had to be sanded away from the top of the fuselage to allow the plastic cowl to line up with the screw plates and the propeller shaft. Since the sanded area is completely covered by the cowling, the aircraft’s appearance was not affected.
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The supplied push-on rubber spinner cone helped in the cowl alignment. Cool air reaches the motor through the hole cut-out in the cowl. These openings are indicated by lines/ridges in the molded part and are easy to find and cut out with a small pair of scissors. Be extra careful of your fingers and hands if you decide to use a sharp hobby razor knife instead of scissors.
Photo 47
Air heated by the motor can also escape through the curved gap between the fuselage and the cowl itself. It is not designed to be a tight fit in the fuselage.
Photo 48
The finished fuselage and cowl really sets off the otherwise all-yellow airplane; especially in the sunlight.
Wings Times Two:
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There is a fair amount of modeling work required to get these foam molded wings ready to fly. The good news is that it only takes a sharp hobby razor knife, a little time and some GWS glue.
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Here is a shot of both sides of the aileron-wing. It is clear where the aileron cutouts should be made. Care must be taken during the cut not to angle the knife or razor bade over to one side. It is best to cut from both sides to prevent errors in the angle of the cut. Make sure to use only a very sharp, new blade in your hobby razor knife. Do not tear the foam, cut it.
Photo 52
The finished cut unfortunately showed a lot of white foam which tended to catch the eye. A 45-degree angle had to be maintained on the leading edge of the aileron. (Ed. Note: This is a problem with most pre-painted foam airplanes. The solution is to take the wing to the local hobby store. Match the wing against a water-based plastic model paint as much as possible. Test the paint on a section of hidden foam to make sure it will not damage the foam. Then paint the exposed hinge areas. Even a paint that only approximates the original color is better than a white surface.)
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Cut the slots carefully into the 45 degree leading edge of the ailerons to accept the aileron torque wires. If necessary, enlarge the hole with a thin toothpick. This was not necessary on the GWS Tiger Moth as the torque rod hole was a perfect fit.
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The ailerons are hinged with paper hinges. The GWS glue gives you time to position all of the parts before the glue cures.
Photo 57
A small piece of scrap foam was glued in the open slot to keep the torque rod bearing in place. Care has to be taken to not glue the wire as well. It is a good idea to thinly coat the wire with either plastic-safe oil or petroleum jelly (very thin coat) first. The scrap foam blocks were held in place with blue masking tape until the GWS glue cured. The wire section going into the foam aileron does get glued in place so do not coat it with oil.
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A yellow highlighter pen did a good job of covering up the white areas. It was best to highlight after assembly because the chemicals in the glue made the yellow tint go red when freshly applied. (Ed. Note: If the color you are trying to duplicate is the right color yellow, the highlighter will work. If not there are other color highlighters but remember the plastic paint tip given above as well.)
Photo 60
The GWS aileron torque rod system is quite unique in how it uses tiny rubber grommets to provide a bearing for the aileron pushrod when it is connected.
Photo 61
At this stage, you have assembled the wing enough to mate it with the fuselage to allow aligning the tail feathers. Once that is done, the top wing can be fitted.
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Each wing has recessed moldings to accept the hard points that will be used to hold the wing struts in place.
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Photo 66 Photo 67
Small screws are used to hold the struts to the hard points. It takes eight of these screws to attach the Interplane struts. Note how the Cabane struts on the fuselage are mounted in photo 67 as well.
Photo 68
Here is a close up view of the Cabane struts. The cabane is attached to the fuselage with screws and the top of each cabane is glued into the slots in the bottom of the upper wing.
Photo 69
This is how the top wing looks when it is removed. The cabane assembly is a bit vulnerable to damage when the whole airplane is not assembled. But as this is a smaller, Park Pilot-type airplane, most pilots will leave it completely assembled.
As mentioned, the horizontal stabilizer is installed mid-way during the wing construction. Once at that point, install it as follows. After the wing installation is complete, the vertical fin and rudder can be installed.
The Tail Assembly:
Photo 70 Photo 71
There was a problem with the control horns on all of the control surfaces. The horns had a tongue that is supposed to push through the slots molded in the control surfaces. There were molded recesses for the horns in the foam, but they were not deep enough to allow the tongue to go all the way through the control surfaces.
Photo 72 Photo 73
To solve this problem–a slot, a bit like a hinge slot–was cut below the surface of the other side of the control. The horn retainer was then pushed into this slot. Now the tongue could reach the control horn retainer.
Photo 74 Photo 75
A little GWS glue was added for good measure and the tongue of the horn pushed into the retainer. This would be just as strong as the original design and had the visual benefit of not having an external plate showing on the other side of the control surface.
Photo 76 Photo 77
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The end result looks good and hides the changes that were made. It is also stronger and more durable than the “stock” arrangement.
Photo 79
The elevators were cut with a razor blade. Care was taken not to mix them up. Each elevator matched the side from which it was cut; in some small detail. They are not interchangeable.
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Slots were cut and holes drilled to accommodate the elevator joiner.
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Hinges were made from the paper-like material supplied with the kit. Once again, the exposed white foam on the hinge line was colored with a yellow highlighter pen.
Photo 86
The elevator halves were “dry-fitted” (no glue yet) and then put aside until after the wing and stabilizer were aligned. Remember to mark the respective elevator halves.
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Cut and hinge the rudder as per the instructions. A lower hinge is added when the rudder is attached to the fuselage later in the construction.
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The stabilizer is centered and pinned atop the fuselage to begin the alignment process.
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Shown here are several rear-view shots of fitting the stabilizer because the camera was actually used to help check the line up. A review of the photo on my PC screen helped me check the relation of the stabilizer to the wing. A tape measure was used to get the front-to-back dimensions right. The area that is glued to the stabilizer required sanding several times to get everything to sit level before the final gluing.
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The short vertical fin is added last and lined up with the stabilizer and the joined in the rear of the fuselage.
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The elevator halves were then glued with GWS glue to the joining wire and hinged to the stabilizer. The elevators were fitted last, because they tend to get in the way of the visual alignment process.
Photo 101 Photo 102
The rudder was hinged to the fin/fuselage. At the same time, the steerable tail wheel was fitted and keyed into the rudder. The GWS glue was used for all of these tasks and left to dry/cure for an hour.
Fitting The Wheels:
Photo 103
A plastic bracket is glued into the fuselage to hold the main front undercarriage. Allow a whole night for this to cure before fitting the legs to the fuselage.
Photo 104 Photo 105
Photo 106
The very lightweight wheels were fitted to their axles using the supplied plastic retainers. The main wheels were too tight on the landing gear wire so a #44 drill was used to open them up to the best operating diameter. A tiny drop of thin CAA helps the retainers stay in place. Do not get the thin CAA onto the wheel itself.
A separate piece of plastic was cut and used to stop the wheels from riding up and wearing out on the inside bends of the wire undercarriage legs (photo 106).
Photo 107
Photo 107 is a shot of the main wheels doing their job!
Photo 108 Photo 109
The tail wheel assembly is fitted at the same time as the rudder is hinged. Make sure that no glue gets on the pivot point.
Photo 110
Photo 110 shows the tail wheel completely assembled and the rudder pushrod attached. Note the “V” bends in both pushrods. The bend allows for trim adjustments and also protects the rudder servo from the hard bumps of steering on the ground.
Radio Installation:
Photo 112
The aileron servo is installed in the center recess of the bottom wing and the pushrods connected to give roll control.
Photo 111
The one-piece wing has grooves molded into it that will accept the torque rods for the ailerons. A single servo drives both ailerons.
Photo 113
The aileron servo connects, using two short pushrods, to the rubber bushed aileron torque rods. Note the V-bend that is used to adjust the center of the controls. This V-bend is used on the elevator and rudder as well
Photo 114
The rear of the cooling duct from inside of the cowl comes out in the front cockpit. This is also the shelf where the battery will go.
Photo 115 Photo 116
Exit holes from the wing bay area allow the power lead for the speed controller and the radio switch to be put in top cockpit. This makes for easy access during changing the power packs and when the radio needs to be switched on/off.
Photo 117
The ESC / BEC is tucked forward in its own cooling channel. Properly cooling the ESC is especially important.
Photo 118
Seen here are Velcro straps that go through the foam floor of the cockpit to hold the receiver and battery in place. The receiver is inside the wing seat area. The battery slides into the cooling duct via the open cockpit. It gets air from the firewall/cowl area. This way, it is easy to remove the battery pack with the airplane fully assembled.
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Two Hitec HS55 servos fit snugly into the pre-molded recesses for the elevator and rudder servos.
Decals:
Photo 121 Photo 122
The manual is very helpful when it comes to applying the decals. It helps to have these really good diagrams that not only show the decal positions, but also has them numbered to match the decal sheet.
The decals are well worth the work because they really do enhance the look of the airplane. A couple of the roundels did not want to stay down. This was fixed with some very careful and delicately applied heat gun blasts. The decals seemed to like the added warmth and have since stayed put. (Ed. Note: Be very careful here. Apply the heat before placing the decals on the surface. Do not heat the foam. If that does not work for you, use a foam-safe water-based contact cement. Use the cement sparingly and make sure no wrinkles develop during the application process.)
Photo 123 Photo 124
Photo 125
The bare fuselage and vertical fin greatly benefit from some decal “color”.
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Photo 128
An all-yellow wing loses its bland outlook when a bold roundel and some black identity numbers are added.
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You could fly this airplane without the decals but the personality of the bare airframe changes because the decals give it character.
Building Summary
Although this is a small foam-molded ARF, it is not a quick out-of-the-box assemble and fly airplane. You can use very simple tools and you can use the glue that came in the box. It does, however, require all of the controls to be cut out and hinged. The tail/fuselage and wing alignment require a bit of time and knowledge to make the task less daunting.
It is a model that you could build in an apartment or large RV. It does not require special tools unless you consider a soldering iron a special tool? Depending upon your choice/purchase of speed controller and battery, this tool may not even be needed.
All of the parts fitted well and worked, with the exception of the horns and their retainers. Nothing was a “show stopper”. The center of gravity came out just right and the recommended control throws were easy to attain.
Ready To Fly:
Photo 131
The finished product poses for the camera on the clubhouse table before getting in some airtime!
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Photo 134 Photo 135
Four views from the points of the compass show the best sides of the GWS DH82A TIGER MOTH 400! Several different angles show the scale lines of this molded foam model. There is quite a lot of detail for a small and inexpensive ARF. (Ed Note: Nice looking airplane this.)
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Here is a little peek underneath before taking her up. Unfortunately, there are no decals for the under-wing surfaces. A quick trip to most hobby shops will yield some British WWII Roundels for the bottom of the bottom wing.
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The cockpit is hidden under the top wing. Perhaps a pilot in the rear seat would add some more realism?
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Time to strut her stuff! A lot is riding on all those little plastic parts. Fortunately they all worked fine.
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As soon as there was little or no wind, the DH82A TIGER MOTH 400 would be in the air.
Time To Go Flying:
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This airplane will take off with no input from the pilot. There is a slight pull to the left at full throttle. To get a totally straight line take-off, the pilot should add some right rudder, but it is not really on the ground long enough to make that much of a difference.
The airplane is not easy to hand launch, so a bit of a runway is welcome. It will hand launch, but it is hard to find a place to hold the airplane for this task.
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In fact, in the video, the Tiger Moth flew right off a small table top and into the air in just a few feet.
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Flying high at first gives you time to adjust the trims. A little bit of down elevator and 5-clicks of right trim on the ailerons, and the GWS DH82A TIGER MOTH 400 would fly hands-off.
Photo 148
The GWS Tiger Moth looks amazingly good when airborne for an airplane of this size. The easy handling made camera fly-bys a cinch. This is an honest, airplane with no vices.
Photo 149
As do all biplanes, it slows quickly when the throttle is cut. Keep just a little power on during the landing approach. Landing speed is extremely slow.
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The Tiger Moth goes exactly where you point it. Wind speeds should be below 10 mph for the best handling. But I have flown the GWS Tiger Moth in winds up to 16 mph or so. Handling was difficult and such conditions are meant only for the more experienced pilot.
Having all four controls working, unlike many airplanes in this class that usually omit the rudder, does provide the pilot with the control authority required for windy conditions, But at just 18 ounces, the airplane cannot be routinely pushed that far.
Photo 151
Please, BE WARY OF ELECTRIC PROPELLERS.–it is easy to forget that the power is on. One accidental bump of the throttle stick and the propeller will, without any warning, be spinning very fast. If a body part is anywhere near the propeller arc at the time, you too might leave a red mark on your foam airplane holder (Ed. Note: That red stain is really only red paint, but it aptly illustrates what can happen with electric airplanes if the pilot is not vigilant.)I
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Notably, the GWS TIGERMOTH 400 will not readily perform inverted flight. It tends to slow down and force you to roll upright again. The airplane also rolls very slowly so keep plenty of height in reserve or point the nose up about 10 degrees before starting the roll.
Rudder in the same direction will speed up the roll. The airplane does have a strong rudder response. Stall-turns and Chandelles are easy, but it is not a god idea to try knife-edges. It just wasn’t designed to do them!
The GWS TIGERMOTH 400 can be flown very slowly. Flat out speed is not that great, but then again, neither was the full-size that fast in the first place. Full power flight times were around ten minutes with an 800 mAh, 2-cell Lithium Polymer (Li-Po) battery.
The supplied motor had plenty of power; enough power to loop the airplane with a short dive first. A Spektrum DX7 transmitter and a 6100 2.4 GHz receiver were used to guide the airplane. The Hitec HS55 servos were just right for the job.
Park Pilot - Observations.
This airplane will fly well in tight park spaces or be at home as far out as you are comfortable. No problem as a Park Flyer. This is a neat little airplane to always have in the car. The extremely short takeoff run and the equally short and slow landings make this airplane suitable for any reasonable size flying field.
Indoor Possibilities?
Personally, I would love to fly this plane indoors. It is not too fast and will turn quickly when needed. However, it is slightly over the one-pound limit imposed by most indoor flying sites. It also likes to fly a little higher than most indoor ceilings except the Lakehurst, NJ Hangar 1 (190 ft. ceilings) and the Williamsport, PA Inflatable Sports Center (the largest in the country; nearly 200 ft. high and 3 soccer fields long).
Summary
The GWS Tiger Moth 400 is a larger size Park Pilot aircraft that would make a very good second airplane in a small flying field. With a good instructor in a standard size flying field, it could also be used as a basic trainer. As an ARF biplane, a little more construction is required than on most small electric airplanes. But GWS makes it simple with a lot of prefabrication and parts that, for the most part, fit together well into a rugged airframe. Costs are low and the airplane looks great.
For more information on this airplane, please go to: http://www.gwsus.com/english/product/airfly/tm400.htm
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Specifications Manufacturer: GWS Length: 30.7 in. Special Airframe Features: Very Light Wing Loading; Great Appearance; Easy handling; Good Wind Performance for Class |
| Notable Positives Looked as good as the pictures on the box. Wheels worked very well on grass. Lightweight and smooth to fly. Takes off in very short distances Flew well in light winds. Very easy to see. Notable Negatives Decals did not stick well to painted foam Top wing difficult to store when removed due to cabane being glued to wing White foam showed up when control surfaces are cut away |
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Posted by Robert McEanruig
on Filed under Park Pilot Airplanes.
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