by Don Piccard
Well, for those of you that have been following the unfolding saga of my attempts to progress with the Pleiades I can pass on a sad quote from the FAA in Albuquerque: "I apologize for a horrible failure in communication." That apology has been accepted by me and my sponsor, but I can not accept the situation that required it.
While the breakdown and arbitrary discrimination against "Pleiades" was caused by the FAA left hand not knowing what the right hand was doing, the fact remains that their control of operations was inconsistent. Inspectors handling the America's Challenge gas race approved balloons flying Saturday night with identical operating limitations to "Pleiades Seven" which was not permitted by an FAA colleague to even register for Thursday's Special Shapes event. End of story.
But, once again, Albuquerque was magnificent. To see the faces of the kids on the ground and the kids in the air is to see that it is worthwhile. It may be big bucks and it may be red tape, but it is still fun and that is what it should be. It is too bad that the old camaraderie is lost to the masses, but now it has grown enough that there are mini fiestas forming within the big one. Wagon circles are drawn up and social circles are formed, yet they are open and welcoming, drawing on the assembled masses. The only trouble is it is hard to find one's way around that great expanse. Each enclave looks like the next.
I particularly enjoyed the Saturday night gas, known as the America's Challenge for gas balloons, even though it was more often called the America's Cup Race. Style seems to be everything in balloon design now a days. The shapes of the modern crop are certainly intriguing. A sphere is the most economical shape to make but the form taken by many balloons there was the "Natural Shape" which is analytically designed to follow the natural conformation caused by the loads and stresses in the fabric of a single load point simple film balloon.
The plastic stratosphere balloon was designed for the most efficient use of the plastic film and is the familiar squash shape. The modern hot air balloons built by Raven used that design, even if under greatly different conditions. When I built N38JT, which was there and still sound after 16 years, I designed it with a single point suspension with redundant suspension lines from a load ring. Those lines went out to a tangent point on the balloon to serve as parachute suspension in case of fabric damage. They would be actuated by cutting the single point loose. In normal service they are superfluous. The primary load system determines the tailoring of the gores.
Now comes a new generation of "Quick Fill" balloons and, lo, they have the same profile if not the same load distribution. They do look nice if you don't look at the design concept. They even have the same "Outey" belly button deflation ports to take the place of the traditional rip panels - always a source of problems. I guess the folks who designed them didn't have the advantage of the computer engineers that guided my invention of that system. If they had, they would have been proportioned just a little differently and would introduce quite a different stress in the skin. (And they might just work a little more reliably.)
If you are not going to hang your load at a point at the bottom, you should use a sphere as you see on the modern European balloons there. (Not unique, Albert Boitard, flying the Canadian entry in the Blitz Cup in Amsterdam in 1950, had a netless spherical balloon.) But then the question is what is the "Catenary curtain" for? Of course the proper curve for the suspension curtain is a parabola while the catenary is the natural curve of the suspension bridge cable without the load, but in a non pressurized balloon neither is correct. Without longitudinal load in the cable there is no equal distribution of load into the fabric. Just plain patches, as designed by Capt. Whittle of Lakehurst ("Whittle Patches") do a much better and much cheaper job.
Both of the stratosphere balloons of my uncle and my mother used catenary suspension curtains. The craftsmanship in the details of the grommets and cables is an art form. Probably, even with 1930's labor rates, a good portion of the cost of construction went into that unnecessary feature, not to consider a good deal of extra weight. My Japanese Fugo balloon used the same design without the fancy beckets. It was super pressured in flight, but below pressure height the stresses were not distributed so it, too, was an engineering error. Some of the current crop still fall into that.
You could notice the profile of the SkyPower balloons during inflation and see that they are not spherical. I tailored the gore shape to account for the shape the balloon takes under the net, yielding a couple of hundred extra cubic feet of volume with less wasted fabric. Yet it is not noticeable once the balloon is up.
I was only saddened by the ugly string balls folks form their drag ropes into. They are ugly because they will tangle and snag when activated. Someday the old geezer will have to drag out the U.S. Navy ground school manual and show these young whippersnappers the right way to do it. How about an Ortho Balloon Ground School in conjunction with the Hudson Hot Air Affair? We could even get into pre-inflation balloon make ready. Any takers?
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