Miss 38 (oz3001)

About this Plan

Miss 38. Free flight sport model, with vintage styling.

Quote: "A 45in span vintage style radio assist model for 1 to 1-1/2 cc engines. Miss 38, by Vic Smeed.

Interest in early gas models has become considerable over the last few years, partly as a reaction to modern almost-ready-to-fly designs which fail to satisfy the urge to build, partly from nostalgia, but mostly from the discovery that flying such models is much more fun. There is enormous satisfaction in actually building a structure rather than sticking a few pre-cut sheets and blocks together and joining a pair of ready-made foam wings, and flying the result is relaxing and enjoyable.

There is one tiny fly in the ointment, and that is that most of the early power models were big; they needed to be for the weight of the early ignition engines, and in those days balsa was unbelievably cheap, especially in the USA. In 1937 you could buy, in America, a kit for a 7ft model for £1 - although in a deluxe version at £1.75 you got a finished prop, airwheels, all the ribs cut rather than printed, and two half-pint cans of colour dope. Cement was always included in kits.

British prices in those days were higher but many of the power designs over here used a lot of spruce and ply and were on average considerably heavier than American machines. In many countries (Germany for example) balsa was never used.

Building a replica of one of the big models today represents quite an investment in materials as well as offering problems in storage and transport. Why not, then, build a half-size one? Although the majestic flight would to some extent be lost, the general shape and much of the attraction could be retained, and a lot of people unwilling to tackle a 7 or 8 ft model might be tempted with a small and relatively inexpensive one. Since scaling up or down is a departure from true vintage, it is not much more of a step to a new design incorporating vintage characteristics, though it is appreciated that this is an approach which the true-blue vintage enthusiast
might frown upon.

Thus Miss 38. Old hands might discern touches of Garami, Effinger, Struck, Shereshaw or Plecan; recent modellers will perhaps find the methods of construction something of a challenge, although it is all straightforward. The intention was free flight or rudder-assist, the latter being quite different from rudder-only control. Only a small rudder is fitted, and should be used gently to produce wide circles. As with a long tail moment, a lifting-section tail and the consequent rearward CG position, tight turns will rapidly develop into spiral dives. Opposite rudder may straighten such a dive out but the excessive speed then means a loop and/or stalling all over the sky, which is not the sort of relaxed flying originally envisaged.

Wings. The flying surfaces are fairly normal in construction, though the opportunity has been taken to use spruce for one of the mainspars, just in case unintentional aero-batics occur. Making the wing panels separately and then joining has always seemed to me making unnecessary difficulties. Far better to build one panel, prop it in place at the correct dihedral and build the next panel on to it, repeating until the entire wing is assembled. The dihedral braces can then be added after a check that all angles are correct.

With both the wing and tailplane tips, the upper spars should slope down to the sheet tip outlines, and this is best achieved by cutting across the top of the flatways spars (ie wing mainspar) and cracking down-ward, rubbing cement into the crack and all round the spar. Vertical sections need to be cut and jointed unless the change of angle is only very slight.

Fuselage. Crutch construction is used for the fuse-lage, the crutch being a frame of 1/8 x 3/8 in strip built accurately over the drawing. Make sure the cross-member ends are cut vertically and that they are located accurately and upright on the drawing. While this is drying, trace and cut the formers; gaboon ply was used for B1, B2 and the cabin top on the prototype, as it is adequately strong and quite noticeably lighter than birch ply..."

Update 13/02/2017: added article, thanks to TonyC.

Supplementary file notes

Article.

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