Myth of the heavy glider, from July RCM&E

[Erfolg]

Although I do not compete anymore, some twenty years since i last competed. I think that perhaps the author of the piece mis-understands why many models were heavier than appears necessary, in this era.

In the days I competed the people to aspire to beat were the Steve Mettams, George Stringwells, Mike Francis, Bernard Henshaw, Bill Bulson, Bill Haley, Dave Fog, Al Wisher and many many other talented flyers and builders. Above all they understood tactics and were keen observers of what mattered.

They all understood that starting higher from the launch than the others, provided a massive advantage. To get high, a fast, high tension launch was a prerequisite, needing a John Goldsmith on a hand winch, later the most powerful electric winch that man had devised.

The trouble a lightly built wing, could not stand these forces, and a big model was better than a small model. So I remember standing in awe of the size of Mike Francis model, and also wondered at how many approx 1" aircraft type alloy tubes Bernard Henshaw had somehow built in his wing (3 per wing).

There was a price to pay for this massive strength, that is their models were all much heavier than say a "Bird of time" out of the kit box or a Gentle Lady even when beefed up.

I can hear our scribe saying, but they will all come down faster and fly faster than our so called floater. Again these guys were no fools, they either instinctively knew or actually knew that L=0.5PV^2SCl. The important bit is the V^2. You do not have to fly that much faster to compensate for the weight.

Yet the big advantage is the extra height gained on the launch. My first spreadsheet was produced to evaluate the advantage of height relative to flying speeds etc, so model flying was educational and provide skills for calculating friction losses in piped systems. The results were a "no brainer" launch height out ways any theoretical advantage from a slightly lower sink rate, by such a margin, the weight did not matter. Particularly that you could see that some were getting over twice the height, from the same line length.

The other advantage of a big model also made observation that bit easier.

What is not addressed is that flying speed relative to the ground and air is a desirable feature for those talented flyers. They did not just sit there, hoping to out hover there rivals, They sought out possible lift areas. Then worked it, or scarpered from sink.

They and their spotters, did not just notice other models, they observed how high or low Swallows flew, any Gull activity, the path of birds flying through, shifts in air direction, temperature changes of the air, where trees were relative to the prevailing wind and so on.

As for me a miserable failure.

Back to the model, electric (glider) models in general do not need such a strong wing (I have about 6 or more sets of super strength over weight wings) for electric flight. Yet the big difference is that these mouldies are as strong if not stronger than the wings of yesteryear, plus they are truer in most cases.

Yet strength is required, today, as that dot in the sky, has a habit of continuing its upwards journey, where ever you go, above a certain height. Spinning down, inevitably puts the model under stress, a lot more than you are lead to believe. Even air-brakes, are hard to manage at height, the model easily over-speeding (that is faster than you would like, if you only knew). Although crow braking does seem to tick all the boxes. Any one who has heard the scream of a descending body, whilst the wings flutter down, will never forget it. Particularly when you try and get that GF body out of the ground, having buried itself beyond the wing roots.

Weight for the sake of weight, is a disaster. Yet super light weight, low strength models need handling carefully, which is probably all but impossible at height. I have noticed that owners of Avas and the one Bubble Dancer, handle them with kid gloves, never seeming to fly in any great wind or height.

Now that the rules limit height and motor run to 200m and i now understand possibly less, the emphasis seems to have moved to speed, for distance and possible zoom. Strength is still required,

I am saying it is a myth that the models were built to be heavy, they were built to be strong, with wing sections to permit travel, yet the design concept would outperform the light weight model of the era.

In this era it is all about reflex, loiter, speed and crow braking, not about light weight for the sake of light weight, it is a balance of strength against duty, which still incurs some additional weight. Some mass is required, to hold the pieces together and to cope with the operating duty, safely.

If still in one peice, I would put my 100s glider against many of the current lightweight gliders, and fancy my chances on a proper bungee(high, force, long pull) bungee aginst many of the current sports gliders.