5th July 2015 by admin | No Comments | Filed in Advice

After suffering the complexities of both fully built up and foam RC Plane wings for about eighteen months, I decided to investigate the possibilities of designing and building wings from solid balsa sheet. The initial inspiration for these came from the Mini-Phase—many other readers must have wondered, as I did, at the simplicity and efficiency of those solid balsa wings. Since then I have built and flown several different slope rc soarers hav-ng solid wings, and have experimented with both parallel and tapered wing planforms and sections. The culmination of these experiments appeared in the shape of Poltergeist, a design that has inter-changeable wings of 50 and 73in. for use as either a fast aerobatic fun model, or a pretty effective soarer.

balsawood rc plane wing

As may be imagined, the density and strength of balsa is proportionate to its weight, and the weight of a 3 x 36in. (12 x 76 x 915 mm) balsa sheet used in the wing construction is shown. Also illustrated are some design studies for different types of soarer wings, along with the density of balsa required to give the wings enough bending strength for the normal flight stresses that each type of glider is likely to encounter. The less mathematically minded will want to know that the weight of a sheet of balsa with a density of 51b ‘cubic ft. weighs 2.oz. (70gm), and the weight for a cubic ft. sheet would be 31oz. (91grn). I discovered that the advantages for this type of construction are numerous. The rapidity of construction is notable as a set of wings need take no more than three evenings to complete including covering. The cost of a pair of medium to small soarer wings is comparatively economic, and they are simple to repair. A dented or crumpled area can be cut out and a block glued in and carved to shape, while a completely broken (sheared off) wing panel may be simply glued together

Right: the Poltergeist 73 sailplane has an all-up weight of 22oz. (625gm) and uses 61b/cu. ft. density balsa. A sheet k x 36 x 3in, therefore weighs 3oz. (12 x 915 x 76mm sheet weighs 85gm). Below, the Poltergeist 50 has an all-up weight of 23oz., and uses 5/cu. ft. balsa (sheet described above weighs 2-2-,oz.-71gm).

Left: example ‘A’ has aerofoil thickness of 6.25%, uses 51b./cu. ft. balsa, maximum loading 160oz. to the sq. ft. ’13’ also has an aerofoil thickness of 6.25%, with 51/cu ft. balsa, but the wing is over twice as heavy and is not capable of withstanding as high a `g’ as A. Example ‘C’ employs a 8.33% aerofoil and 6.51b./cu. ft. balsa, and can withstand a breaking strain of 60oz. per square foot.

Again using the exposed fibres of the break as a natural key. A designer using solid wings can afford to be adventurous as the problems of tapered, swept and even crescent wings are consider-ably eased by the absence of spars and braces that have to be lined up. In fact, tapered wings are to be preferred for this type of construction, as this planform concentrates the bulk of the wood (and its strength) at the point where it does the most good, at the wing root. Medium to low aspect-ratio wings are best to start with as, although they are heavier for a given area, they are also stronger. (Mathematics applied to this problem proves that a RC aircraft wing of 6:1 has a loading strength of almost nine times that of a wing of equal area and an 18:1 aspect ratio.) The aerofoils used on the Poltergeist design are ideal for this type of construction, being not too thick, basically flat-bottomed with a low cambered mean line, and having a sharp leading edge. Other thin (5 to 10 %) aerofoils suitable are the Gottingen 795, Sigurd Isacson 3306, Eppler 387 and Eppler 193. After deciding on the density of balsa required, the modeller may descend on the local shop armed with a spring balance and a sheet of masking tape (the latter for providing an attachment point on the balsa for the balance—shopkeepers, the exact weight of wood cannot be found, choose some slightly on the heavy side, as lighter wood could fail under a lighter loading, and prove to be a false area for saving weight. It is better to take the excess weight out of the aircraft fuselage, where excessive loads are more likely to be caused by a crash rather than flight stresses. The dimensions of most wing panels will require that a number of sheets have to be joined to pro-vide a wing blank. Any sheets heavier than usual should be concentrated at the root and at the centre chord position, to provide the best effect in the strength of the wing. A combination of edge and scarf joints using PVA glue gives a suitable amount of strength with-out too much complexity, and these can be held together with masking tape while drying. When dry, the wing “blank” may be cut to plan outline with a stout bladed knife, using a steel straight edge, preferably of sufficient length to reach from root to tip. Trim the root and tip ends, and mark on them the chosen aerofoil.

solding rc plane wing

Check and re-check at this stage to ensure that a right and left wing will result, and not something like a right wing and a left wing with a swept forward trailing edge. If the wing has a tapered thick-ness, this has to be dealt with next. Fig. 1 shows the wing at this stage, with a taper line marked on the leading and trailing edges. Saw-cuts are made, passing through the waste wood down onto the line, and these prove a great help when carving down onto the taper. A razor-plane will be found invaluable during this, and following, stages. If a definite procedure is followed while carving the aerofoil, no problems should result, and I have found the method about to be described works well. First, mark lines tangential to the aerofoil drawn on the root and tip, as shown in Fig. 2. Using the straight edge, join the points where the tangents emerge on the wing blank surface and edge, and carefully carve down to this flat area outlined. This procedure is repeated, as in Fig. 3, until a rough aerofoil appears, at which point the razor-plane is swapped for a sanding block in order to complete the shaping. Templates providing the aerofoil at intermediate stages along the wing are not essential, but may assist those who are doubtful about their ability to carve down to a straight line. Very little is left to do in order to complete the wing. Wing tip blocks are the same as any other type of wing construction, having the grain running across the chord. The ailerons are really simple as all that has to be done is to cut them out and provide the clearances for the movement.  No more false trailing edges or hinge block to be fitted, the completed aileron is just cut from the wing. Joining the wing panels should cause no problems, as modern glues are strong enough to ensure that a well made joint is stronger than the wood surrounding it. Small models only require a glued butt joint, while the Poltergeist designs have a butt joint with the addition of a thin ply cover strap on the underside that acts as a reinforcement and a rc plane wing, locator. Should any additional bracing be required, ply joiners may be simply inserted into the root. Should it be thought necessary,harder balsa spars may be laid into the wing although, if the wing has been correctly built and stressed, such a measure should be unlikely. The wing is suited to any form of finishing method, although the use of heat-shrink film can be recommended, as this gives a very professional finish with the minimum time expended. Why not give this type of construction a try? There is every chance that the wings you will be building will be more pleasing in their efficiency and ease of repair than any other you have used.

All materials used in this guide to construct the different types of RC Plane wings have been purchased from – They are our preferred supplied for anything related to remote control aircraft.


How to Publish a RC Helicopter Article with us

5th July 2015 by admin | No Comments | Filed in Advice

As promised, we now give detailed pointers for those who feel they have something to offer but don’t quite know how . . . .

HERE AT Space Elevator we are to be of draughtsman like quality often asked to explain just what Pencil drawing is adequate, on car-is necessary for a reader to submit tridge paper, shelf paper or even to us in order to “break into print”. wallpaper—the back, of course. (We It takes a long time—probably at the have had drawings submitted to us `wrong time’—to explain the details on embossed wallpaper—but this is to every telephone enquirer, so we being unnecessarily masochistic). have jotted down some guide lines Apart from making sure that all which will help to point would-be the components are drawn, do be contributors in the right direction. certain that the following items are Certain things hold good whether noted on the drawing—not just in one is aiming to have published a the write-up : complete model design feature

1). Balance point (e.g.) article, a general or technical article,

2). Designed wingspan or simply a photograph, so—if you

3). Engine capacity (or range) have always wondered just what you

4). Thrust offsets (if none, state) should send, and in what form you 5). Dihedral 53 3, should send it, in order to have the

6). Washout 33 ,, best chance of its being accepted,

7). Wheel sizes used then we suggest you read all of this

8). Control surface throws little piece, and keep it somewhere

9). Weights—bare and all-up handy for reference . . .

The write-up will depend on the As we just inferred, the types of complexity or otherwise of the material involved fall fairly neatly design, from the actual “how it’s into three categories :

1) Plans built” point of view, but generally features,

2) General/technical arti speaking it is better to concentrate des and

3) Photographs.

We’ll take on the trickier, less obvious parts of them in this order . . . the construction, than an actual, sequential “stick A to B” saga. What is required, however, is a good intro-ductory section, giving the back-ground of the design and how it was developed, or came into being. And, of course, with radio controlled models, really the most important

Plan features Three basic constituents—full-size working drawing, write-up, and photographs. The drawing should be dimensionally accurate, but does not have

part of the story is “how it flies”—so give as much detail on the model’s handling and flying characteristics (from the pilot’s point of view—as distinct from the introductory description) as you can. Emphasise its best points, and detail any particular type of flying in which your model excels. The photographs are very often the most difficult item for many rc helicopter modellers, it seems. We like to maintain picture quality, for reproduction, but “good quality” is a very subjective description! So, if you are not sure about the quality of picture from that Box Brownie of Great Uncle Jeremiah, it may be best to enlist the aid of a friend who is known to be a pretty competent camera wielder. What photos are required? Well, if you have the opportunity to arrange some shots of the model in different stages of construction, please do. Most people do not think of doing this because they hadn’t thought about possible publication at the time they were building the model. (Maybe you can do it with the next model—it won’t put a jinx on it!) For shots of the finished model, two or three views, showing its most interesting angles, plus one or two close-ups of particular details that need to be shown, plus an “installation shot”—and, finally, a posed picture of yourself with the model. (For more about how these should be arranged, see under “Photographs”, later on.) Additionally, if you have the necessary friend with telephoto lens, some “fly-past” shots are always welcome. Whenever possible, subject tc accepting the plan-feature material. we do like to have the opportunity of examining the model, and seeing it flying. This we can usually arrange when the designer lives within about 50 miles radius, or perhaps will be flying his model at a meeting which we also plan to attend. On these occasions, we would normally be able to take some photos ourselves—including the rc helicopter in-flight shots.

General and technical articles

A balanced presentation is what is needed here, rather than a solid mass of unrelieved words. So try and include a number of illustrations, whether they be photographic or diagrammatic. Sketches may be done quite roughly, in pencil or ball-point, so long as they convey what is intended. Our art department will draw them up in ink for reproduction. Don’t leave blank spaces in the text, with “sketch of wheel goes here” type of annotation. The thing to do is to give your drawings (not the photos) figure numbers; these are then referred to in the text (like “see Fig. 3″) to tie up with the drawings. Give your sketches numbers in order of appearance. Handwriting doesn’t seem as readable as in olden times, so we really do prefer typed articles. Double spaced. But, if you do not have access to a typewriter, or—preferably ( !) a typist—do not des-pair; if that article really has some-thing important to say, then we’ll read it somehow! But please write on every other line of some ruled foolscap paper. In either case, write or type on only one side of the paper. (Articles can become mysteriously shortened otherwise; our typists are used to their “copy” being one-sided!) How long should your article be? This is a question that many would-be contributors ask, but it has no hard-and-fast answer. We usually say: “Write what you feel you have to say.” If it is too long, then we will do some trimming. If it is too short, we may ask you to elaborate on some points that may not be clear. Normally, we like to have articles that make between two and three magazine pages, but a single-page article is also very welcome. On the other hand, sometimes a subject of special importance (like silencing) crops up, and may warrant becoming a three-part series, each part of two-to-three pages. So don’t worry too much about length; simply write what you feel is the important body of the subject, with-out embroidering it. And read it through several times before sending it to us, to make sure that you have been as clear as you were able, and have not repeated yourself unintentionally.


As we said earlier, this is where the majority of would-be contributors seem to fall down. It is not always on the technical quality of the pictures (not much of a problem with today’s cameras—even the relatively inexpensive types) but in the way they are taken. By this we mean that scant attention has been paid, in most cases, to the background, or to the angle at which the model has been posed, or what the light was like (whether it was suitable or not suitable for taking the photograph in the first place). We could write several articles on photographing models, but will con-fine ourselves here to some really basic pointers. . . .

1). If you must snap the model in the garden, do try to ensure there is a good stretch of open lawn behind it—not the rose garden or the dust-bin. A higher camera angle will enable the undesirable background to be eliminated (use a pair of steps, rather than standing on tip-toe). Better, of course, to take the pictures on your flying field—unless you do not have a mown strip. However, pictures of you with the model, are much better taken at your actual flying area than in your back garden, so at least these can be taken on the field, if not the static posed shots.

2) Before taking a static (on the ground) shot, prowl all around the model, so as to see its most photo-genic angle/s through the view-finder. Find its best side—or the angles which show the most interesting features or markings, as well as actually showing off the general configuration.

3). Best conditions for most mod-el photography are what is known as “Hazy Bright”. That is to say a good bright sky, with plenty of light around, but without any direct sunlight. This means that the shadows cast by the model will be soft and won’t “fight” with the shape of the model itself. In some conditions it may be necessary to use a tripod, to avoid camera-shake, when using a relatively long exposure (below 1/60 sec.). Use the smallest lens aperture (or “stop”), as this will provide good depth of field and ensure those wingtips do not go off-focus.

4). Constructional shots, done indoors, are best made in “existing lighting” rather than with flash, as the latter’s illumination falls off very rapidly (inverse square law, an’ all that), whereas, with a couple of 100w lamps, about 4 or 5ft. from the subject, nice even illumination is given. A tripod is a “must” for this, of course, as the exposures are likely to be in the region of or -} sec.

5). Action shots. These are some-thing on their own, and—unless you (or your friends) own a telephoto lens (135mm or so)—it is usually not worth attempting as the image will appear so small. If you are equipped with a “long” lens, how-ever, then you probably won’t need to be told how to take the pictures What are needed are several in-the-air shots—plus one or two showing the model and the horizon, to give a “reference”. Best time for this is when it is making a landing approach. Needless to say, the best conditions for action shots are bright sunshine, with some clouds around (use a yellow filter, with black-and-white film) for best effect. Bright sunshine so that you can use a fast shutter speed combined with not too wide an aperture. (A shutter speed of 1/500 is usually right for power models, and 1/250 adequate for glider launches, to “stop” the movement. Of course, these settings may be varied according to the conditions, model speed and so on, but try not to find yourself in the position of having to take the photo (because you arranged for your club mate to fly the model, a week ago) with a thundercloud overhead, and settings of 1 60 at f2.8. If it’s like this—go home, and arrange another session! 6). We greatly prefer black-and-white photographs. This is because colour prints do not always reproduce faithfully the actual tonal contrast when rendered in mono-chrome. En-prints, or contact sheets, will be satisfactory provided we have access to the negatives. If you are providing the enlargements, however, then you should note that our preferred size is “half-plate”. That is 44 6-lin (12 16.5cm), single-weight, glossy finish.

Identification! Please put your name and address not only on your article, but on each and every photograph you send to us. If you wish to include suggested captions, then we suggest you simply number the photos, on the backs, and key these numbers to a separate sheet giving the captions. But if you do write on the backs of photo-graphs, then please—please—pack them back – to – back face – to – face You’ve no idea how many good prints have been ruined by being piled one on top of another, all face-up, with the ink still wet. Even ball-point ink takes time to dry and the ink off the back of one print transfers onto the face of that underneath, and so on! (Once people reach the stage of being on the brink of actually posting the photos, article to us, they don’t hang about for the ink to dry!) First approach We do like to see all the material you have to offer—drawings, write-up, photographs—in one go, so that we can give a definite “yea or nay”. If, however, you feel you must have at least some indication of whether we might seriously consider your design before drawing it up and writing the article—then by all means send us a photograph of the model, together with its salient measurements, power requirement etc. We will not be able to say “yes, we will publish it” at that stage, but at least we can say “Yes, if your material is up to standard” or “No thanks, we already have something too similar”. But, remember, it is only when we have been able to assess all the material that we can make a final decision.

Try your luck . Hardly luck, really—contributions are normally accepted on merit ! Anyway, the foregoing should have given you a good idea of just what is required for any modeller to “break into print” with his original mater-ial.* We are always on the lookout for new designs, articles and good photographs, and the Editor will be glad to have the opportunity of seeing your material, and will be happy to give guidance when sought . . . but not on the ‘phone, please!

*Original—yes—and never ever send the same material to two journals at the same time. This infuriates Editors and you are likely to be blacklisted!

RC Models Product News

5th July 2015 by admin | No Comments | Filed in RC Model News

THIS MONTH, we start with  one of the most striking looking 100in. Standard Class soarers yet to come our way—Veron’s sleek 99 in. (2521mm) span, 2-function Vortex. This features an unusual two-piece fibreglass fuselage, a white-pigmented moulding that is “broken” just aft of the wing trailing edge. The wing and tailplane roots have clearly marked positions for their locating dowels, ply reinforcing plates are already in place inside the wing root fairings, and the total weight of the fuselage as it comes out of the box is 1 loz. (310gm).  Although the fibreglass mouldings seem in take up a lot of the compact box, room is still left for a large amount of balsa and ply for the wing and tail. Wing construction uses Veron’s usual system of slotted leading and trailing edges with die-cut balsa ribs and, in the case of the Vortex, spruce spars. The die-cutting of all the balsa ribs is excellent, while the ply ribs and dihedral braces are also die-cut but will generally need the use of a knife to remove them clean-ly. A polyhedral layout is used for the wings, which have a slim, flat-bottomed aerofoil with the use of spar webs and upper leading edge sheeting to add rigidity and retain a true form. The all-moving tailplane and large, aerodynamically balanced rudder are built up along the princi-ple of a leading and trailing edge with a zig-zag system of ribs, with Ain. sheet spars outside the ribs, giving the surface a simple symmetrical aerofoil when covered. The kit hardware includes a thick opaque ABS radio hatch, pre-formed wing dowels and aluminium tubes, cable-in-nylon tube linkages with adjustable connectors and quicklinks, rudder horn, all-moving tailplane horn, hooks and buttons for wing retention and wire in brass tubes for the tailplane fixing.

rc soaring

The rolled plan is clearly printed, and is in two parts which have to be joined to obtain a full length plan of the wing. Veron’s usual complement of covering tissue is included, and a large name transfer will underline this unmistakeable soarer’s identity. Kitted to Veron’s high standard, the model promises a good performance, and has the sort of looks that could convert many modellers to the 100S scene. The next item on the review bench should stay firmly on the ground, as it’s Irvine Engines’ latest excursion into the racing car field, the s scale, .19 to .21 powered Associated RC1. With a wheelbase of approximately 12 x din. (30 x 15cm), the car uses a 2mm Dural plate chassis and, in our “F” version review sample, a hardened steel one-piece rear-end pressing for use with a Veco .19.

Both these components have all the necessary holes for mounting the various assemblies which are, as usual for this type of kit, packed individually in plastic bags. Oilite bearings are used on the front wheels, rear axle and clutch bell. The clutch has to be assembled, a feature that will simplify any tuning that the builder knows has to take place. Both front and rear wheels have the hubs andityres bonded together, the front having I. Ain. and the rear using tin. tyres. Remaining packages contain the brake parts, the r, c equipment mounting components, Sullivan fuel tank, body mounting pillars and tubes, plus the various wires, springs and connectors required for an efficient linkage system. The instructions are in the form of a booklet that contains numerous photographs to help in the construction as well as hints and tips to get the best out of the car. Some of the best lexan mouldings we have yet seen provided the body and rear wing, ours being for the Lotus 79. This kit deserves top marks whether they are awarded on the grounds of its completeness, or its potential performance. Pliers are an essential part of any modeller’s workshop, and Irvine Engines’ attractively packaged set of six light duty pliers should fill most requirements. The set includes side cutters, two pairs of snipe nosed pliers, two pairs of wire forming pliers (one pair having combination jaws) and a pair of flat nosed pliers. Supplied in a plastic wallet with individual pockets for each pair, the pliers have a brushed steel finish with black plastic handles, and will likely answer the prayers of enthusiasts who chose designs that use dozens of rigging hooks! An attractive new release from Irvine is the Pilot Models Divine Wind, a 65in. (1650mm) span aerobatic sloper for 2 to 3 function radio. A. fully built-up construction is fea-tured, which should present no problems to anyone as the kit is apparently totally prefabricated, with even the wing spar webs cut to size. The slightly tapered wing is built along traditional lines, with a “D” box leading edge and capped ribs, using hardwood spars and a ply dihedral brace, while the all-moving tailplane features an all-balsa built-up structure. Large balsa blocks are used to top and tail the fuselage, which is basically a box section using balsa sheet sides with ply formers and doublers. There is a vast amount of sheet and strip balsa in the kit, along with some very cleanly machined balsa blocks. A number of high quality accessories complement the kit, these include leaf and pin hinges, control horns and torque rods, dowels and tubes for the tailplane, plus the necessary screws and bolts for their attachment. Completed by a very cleanly moulded clear canopy and opaque cockpit, and a “blueprint” style of plan with both Japanese and Eng-lish annotations, this kit will be welcomed by aerobatic slope pilots who like building, but not cutting things out. Many models are described as “almost-ready-to-go”, but Pilot kits’ .09-10 powered Sea Master II deserves the tag. Requiring only the addition of the engine and 2-func-tion radio to complete the job, this 26,1in. (675mm) long craft has its yellow ABS hull and deck already bonded together. An aircraft type engine is needed, as the kit contains “a unique water-air hybrid heat sink”, an unusual device that looks vaguely like an overly thick car engine heat sink, having a duct through it for cooling water. Apart from the hull:deck:radio box and cover mouldings, this kit is almost all hardware package. A large packet contains fuel tank, liquid (plastic) cement, two types of tubing for fuel and cooling water, heavier tubing for the exhaust outlet, self adhesive Velcro and seating tape for the dummy engine cover ‘radio box hatch, and a number of screws and hooks. A final touch, indicating the completeness of these kits, is a large die-cut ply sheet that provides the boat’s starting and storage cradle. A sheet of self-adhesive decals completes the Sea Master, which when finished looks dramatic and could have a snappy performance.

irvine models

Irvine provide something else for the marine maniac this month, in the form of Radio-Active’s prop-shaft assemblies, our samples of which all have a 3-blade 30mm prop, and shafts with lengths of 6, 7, 8 and 9 inches. Irvine and Pilot models close this month with jimmy, a 581in. (1490 ram) span sailplane, of a design that strongly reminds us of some F,’F towline gliders. With an all-up weight of 21oz. (600gm) including the 2-function radio, this model is suited to electric power, and details are given for the installation of a Mabuchi RS-380. As with the Divine Wind, the kit is extensively pre-fabricated, with a great deal of strip and sheet wood being included. Linkages to the rudder and elevators are by a closed-loop system, and a package contains a length of braided nylon cable, tubes and horns for this arrangement. The final touch in this kit is a 200ft. (60m) length of “bungee”, complete with a storage spool that has to be built up from a die cut ply sheet. Certainly not a high performace model, but ideal for a couple of hours’ carefree flying on those calm summer evenings. An excursion into tomorrow’s world has been provided by Avicraft, who have sent us a bottle of the new Tri-Flon. Those modellers who occasionally find time to watch the “box” in between sticking down formers, may recollect a recent programme which featured, as one of its items, a new PTFE lubricant. This was demonstrated to be capable of efficiently lubricating moving parts under the sort of pressures that caused conventional oils to pack up. Intended for virtually any use, this may be particularly welcomed by owners of racing engines, where it could add a few extra revs to the engine. Two offerings to the Club-20 scene come from Cambria in the shape of a pair of Fun-fighters (and a matched pair at that), the P-51D (bubbletop) Mustang and a Focke-Wulf Fw190D. Both kits span 43in. 1092mm) and are intended for 2 to 3-function RC with a .15-.25 motor. The kits themselves are similar in presentation, both having veneered foam wings, the Mustang’s weighing 3oz. (85gm) left and 31oz. (90gm) right, while the Fw’s are 24 and 31oz. (65 and 90gm) right and left respectively, in our sample. Both models use a simple fuselage construction with ply formers and doublers and s sheet sides, with block balsa contributing to the nose contours. The cowling of the Fw uses machined balsa blocks to pro-vide the nose, while the change from the near-square section of the fuselage to the circular section of the radiator is obtained by insetting triangular outline sheets. The tail surfaces of both models are from sheet balsa, which has been cut to outline shape. Both kits have beautifully formed cockpit canopies, and vacuum-formed exhaust stacks, while the hardware includes motor mount, torque rods, nylon bolts with threaded hardwood beams, glass tape, hinge material and the various nuts, bolts and screws for fixing the engine and control horn. Rolled full-size plans are included, along with the highly detailed instructions that are normal for Cambria. Completed by a decal sheet that includes the u c door outlines for the bottom of the wings, both of these models are bound to take the air in numbers during the summer months, re-enacting the air battles over the Ruhr. (Also distributed by Ripmax). A variation on a theme has been released by Precision Petite, in the form of their P2 drill fitted with a three-jawed chuck. This drill will take tools up to iin. in diameter and provide a more secure grip to odd sizes of drill. The three-foot cable attached ends in a pair of mini banana plugs, to fit the existing transformer control unit. A new recruit to the ranks of the Trewest designs is the Slingsby Kite, a 120in. span class-two scale model for 3- or 4-function radio. Fuselage construction is not com-plicated, using ply formers and balsa sheeting, while the wings have spruce spars with balsa ribs and sheeting. As usual for Trewest, the plan comes complete with a duplicated sheet of instructions. Also available to support the plan is a moulded canopy—plus a documentation pack, which takes a lot of the work out of researching the proto-type.