Late Night Final (oz1412)

About this Plan

Late Night Final. Free flight rubber contest model. Model Aircraft March 1959.

Quote: "THIS model was specifically designed for a beginner, but I was so pleased with my original that I have temporarily discarded the diamond lay-out in favour of the slab-sided model.

The model is an economical minimum competition sixe of 40 in, using only 18 yd of 1/4 in flat Pirelli. The layout is straightforward and construction should present no difficulty, provided that you are not too ham-fisted. Remember, building a rubber model is not carpentry, and always keep the scales handy to check the weight as you build.

Wing. This is of geodetic construction up to the first dihedral break - from there conventional straight ribs are used. It is possible to build a lighter wing than the one drawn by using a triangular box leading edge built up from 1/16 x 3/16 in medium balsa, and a 3/16 x 3/32 in trailing edge, but beginners are not advised to do this.

It is important to build in the following warps during construction to aid stability. Left wing tip, 1/16 in under the trailing edge at the tip. Left wing panel flat. Right wing panel 1/16 in under the leading edge at the dihedral break. Right tip flat.

Tailplane. Use medium soft wood here and build in the following warp. Trailing edge to be lightly doped on the underside, to give a slight positive warp at the tip.

Fuselage. Construct the side frames on the plan and join together using cardboard jigs. A stout piece of cardboard is used for the jig, and this has a rectangle cut out to the size of the fuselage. Make one for the nose, two for the centre of the fuselage, and one for the rear. Make the distance to the datum line from the bottom of the cardboard 3 in. The fuselage is then easily assembled on the building board and will line up perfectly.

Covering. Cover the fuselage with light Modelspan in black or red, and for the wings, tail and prop use Jap tissue. Be certain to stick the tissue to every rib and use only banana oil on the prop.

Trimming. After hand gliding and adjusting the rudder to a 100 ft right-hand circle, wind on 300 turns. The model should turn right under power with a perfect entry into the glide. If height is lost in transition put more pre-tensioning turns on the motor, or if this fails move the CG forward and retrim. Be sure that the prop folds level with the port fuselage side, otherwise a spin may occur in windy weather due to extra side area at the front.

Gradually increase the turns up to a maximum of 800. The model is almost certain to powerstall at one stage, and this should be overcome by careful application of 1/64 in right side thrust. if this fails, use down thrust, of which the original needed only a small amount.

As a guide the model-should clock 3 min on 500 turns and over 4 min on full bang - the best of British luck!"

Update 1/08/2012: replaced this plan file with a clearer copy thanks to aeromeddler.

Supplementary file notes

Planfile includes article.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction