Friday, April 11, 2014

LTA 20-1 poster

Of all the LTA-20-1 memorabilia I have, this is my favourite. It shows the vehicle in its most positive light, and makes something that is essentially a big spherical bag of helium look rather svelte and technically feasible as a flying machine. The signature in the lower-left corner says: R. C. Beaussard. He or she has done a good job on this picture.

R/C models and computer simulations of this vehicle clearly demonstrated that it was highly maneuverable. Turn on a dime? No problem. Those engines could be vectored and throttled, so lots of different types of motion was possible. The other cool thing was that it made use of the Magnus Effect – hence the company’s name, Magnus Aerospace – to create additional lift for carrying stuff. Its helium-filled spherical envelope was mounted on an axle, which in turn was slung across that huge curved wing-yoke structure. Spinning the sphere opposite to the vehicle’s direction of flight – that is, if some super villain dropped you on the top of the sphere while it was spinning, you’d find yourself clinging for dear life while the sphere’s rotation tried to fling you back into the blimp’s wake J - created aerodynamic lift. So, you got aerodynamic lift from spinning the sphere, and static lift because it was full of helium.

The problem was that maneuverability and the unusual way of creating aerodynamic lift came at a high price. If I remember correctly, its lift-to-drag ratio – L/D in aerodynamics-speak – was always somewhere between 0.9 and maybe 1.1 at best, but usually a little below 1. When a 747 is cruising around, it has an L/D of something like 17, and a sailplane has one of maybe around 50. Drag is the cost of creating lift, so if you can get 17 units of lift for 1 unit of cost, or 50 units of lift for 1 unit of cost, that’s pretty good, but 1 unit of lift for 1 unit of cost makes me scratch my head. For a small, scale model flying over a model railroad layout this wouldn’t be much of a problem since when the batteries died, the beast would just be left floating around in the house until rescued, but for the real-McCoy, this could be trouble.

But, lift cost aside, I still like the way it’s depicted in this poster.

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