Pink Elephant (oz7666)

About this Plan

Pink Elephant. F1A glider. 80in span.

Quote: "Free Plan Feature. John Cooper's 80 inch span F1A glider - Pink Elephant.

WOULD YOU LIKE a simple to build and easy to fly F1A class glider that will give you a good chance of winning contests; if so, then Pink Elephant could be just the model for you. My first gliders were own designed creations which only flew well in about one contest in three. After several seasons of placing in the lower half of the contest results, I decided that I needed a radically different sort of model if I was ever to win a contest. The most reliable and consistent model around at that time (the late 1960s) appeared to be Dave White's Rolling Stone (oz9490) and so I built a couple of those and slowly started to gain contest successes.

Since that time all my models have been derivatives of the basic Rolling Stone although some of the models look so different that a casual observer would not realise their parentage. Development has produced three different styles of model, each for use in different weather conditions. All the models have the same basic layout ie wing chord, fuselage length and tail size. The variations are in the wing section, wing structure, tip shape and the towhook system. The three styles of model are:

1. WINDY WEATHER MODELS, using a thick well-undercambered wing section with a very hefty I beam spruce bar and a semi godetic structure. These models will withstand being towed in any wind strength yet encountered and are strong enough to take most rough landings with only superficial damage.

2. CALM WEATHER CIRCLE TOW MODELS, these use either a thick Shoat wing section with a light I beam spar, a small turbulator spar and a semi geodetic structure, for use in thermally conditions, or a Benedeck 6356b wing section with a D box sheeted leading edge for 'dead' air conditions. Both use a Russian style circle tow hook system.

3. GENERAL PURPOSE MODELS, these are used for any wind strength between 5 and 15 mph ie the conditions most usually encountered in Britain. Pink Elephant is this type, and is the model which most shows its Rolling Stone ancestry. These models use a fairly thick Mike Burrows wing section featuring plenty of undercamber and with a multi-spar, straight rib wing.

Presumably, due to the turbulating effects of the three upper spars on the airflow over the wing, this type of model displays a far better ability to centre into thermals and rapidly rise to the top of a pack of thermalling models, than models with different wing surface structures.

Five models have been built to the plan presented here and each one has had numerous contest successes, most importantly helping me to qualify for four consecutive World Championships team places and reaching the flyoff at the 1973 World Championships (the less said about that flyoff score the better!)

Construction of Pink Elephant is fairly simple and could be undertaken by someone who has built one or two medium size beginners free flight models, I can build one in two days and go flying on the third. Since the construction is generally straightforward, only the deviation from normal practice are mentioned.

Wing and Tailplane: I cut my ribs for both wing and tail over-length by using the template sizes shown and only cut them to size at the final construction stage. After pinning the leading and trailing edges to the plan, the ribs are put in the correct positions and the rear end is then cut to ensure that the rib fits exactly for length. Each trailing edge to rib joint is then gusseted. Although this method is rather fiddly it does give a stronger structure than that obtained by use of the more usual notching which can weaken the trailing edge..."

Direct submission to Outerzone.

Supplementary file notes

Article pages, text and pics, thanks to algy2.

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