Quantum

Dave Broyles © 1997

I was diving out of the sky at 80 mph. My right arm was broken and totally unusable. I am right handed. I had one chance, my parachute. I let go of the control bar with my left hand and went for my chute handle. The instant my hand released the control bar, the glider pitched up, the cross bar broke and the glider went into a violent spin. I made a clean grab, ripped out the chute and threw it. Nothing happened... Bummer.

I reached around for the bridle. But I was spinning 2 times a sec and the G force had me at the end of my harness lines. The bridle was no where to be found. My tow line was still attached. I started spinning around the towline sort of like a bezerk stunt kite. I hit the ground on the up swing, and dislocated my ankle. Actually an optimum result considering the circumstance.

I was happy to be alive, and also happy that a friend had gotten most of the accident on video tape. I was using a 22 gore High Energy Sports chute. Very new, and with a fresh pack. Why didn't it open and set my sorry butt on the ground like it was supposed to. I copied the tape and sent it to Betty Pheiffer of HES to analyse. Betty looked at the tape dozens of times. Her conclusion was the same as mine. The airspeed of the glider spinning down was too slow to get the chute to inflate. This bothered Betty a lot. She would have much prefered that I had descended under an open canopy.

I healed. It took a long time. My arm had been reduced to garbage. The bone was broken in seven or eight places. It took 2 operations and several years to heal.

Meanwhile Betty had been thinking. The tone of her thought was that several people had come down under spinning gliders where the chute didn't open. Her conclusion was that we needed a reserve for hang gliding and paragliding which both opened more quickly and at a slower speed. Now, she knew that PDAs were a step in the right direction, but PDA's tended to be less stable.

She confered with a skilled parachute designer, Bill Gargano about changing and refining the design of round canopies for a lower sink rate. Bill had some ideas in his head, so Bill and Betty went into pardnership to try some of his ideas. Bill came up with a design that was more complex than the simple triangular gore parachute and also put all of the latest construction ideas into it to make it light as well as strong. This design was not so complex as the anular ring parachute, which was a competing concept, but looked and packed like a traditional PDA. In reality, the shape of the canopy was somewhat complex, needing gores that were not a simple triangle. The mouth of the canopy was smaller than the maximum diameter and the cross section of the side of the canopy was a sort of airfoil.

Traditional round parachute canopies have a drag coefficient of around .85 compared to a flat board. Why, you may ask, do we not use a barn door as a drag surface instead of a canopy, if the canopy can do no better than 85% of a flat plate. Well, the barn door doesn't fit as well into a little bag, and also it has a tendency to bash the pilot on the head when it reaches the ground. On the other hand since it is already open, opening shock is negligable. Due to the convenience factor alone, the barn door has been ruled out as a drag device. That a barn door of sufficient area would probably weigh enough to add considerably to the weight to drag ratio and tend to squash the pilot and glider flat instead of saving them are additional factors.

Since a flat plate is ruled out, we have to do research. Aerodynamic experimentation shows that it is easy to design airfoils which will out perform a flat plate airfoil in the production of lift. Simple reasoning then implies that it should also be possible to create an airfoil that will outperform a flat plate in pure drag. This was Bill Gargano's goal.

So the Betty and Bill show got into high gear. Bill has vast experience designing canopies, and he put all of his best ideas into this new design. Then they took the canopy out to test it. First they tested it for sink rate. They put the canopy on a skydiver and added extra loading and an istrument pack. They also took along a camera woman who was light with a big canopy to come down slowly They went to 10,500 ft. The game play was to have the skydiver jump out with the test canopy immediately followed by the camera woman who would video the test parachute. Bad idea. The test canopy sank so slowly that the camera woman immediately got too low to video the canopy and could never get back up to it. Well, try again. This time they had the skydiver jump with the test canopy first, and wait and then the camera woman. She was flying a really big ramair canopy and the video showed her flying around and around the test canopy until she finally sank below the test canopy and left it behind. Bill and Betty had been hoping for an increase in drag coefficient to maybe 150% compared to a flat plate. What they got was a canopy with a coeffieient of 2.3. What was the down side??? Well, it had a Pulled Down Apex so it should be unstable, right. Wrong. Apparently, the aerodynamic forces that made the canopy sink so slowly also stabilized it as well.

Then they tested it for strength. They had two sizes big and little. They started with the little one. They loaded it with a test dummy and extra weight, then threw it from a plane flying 124 mph. A few things broke. They modified the design a little, and kept testing. Finally they completed a series of 3 drops with 331 lbs at 114 mph with 100% success. They took a big one, attached it to a 240 lb. test dummy and added another 90 lbs. for a 330 lb total and dumped it from an airplane flying 135 mph at 500 ft. No damage except for the shock to the test dummy. I would swear there was a surprised expression on the face of the dummy. That dummy had NEVER been stopped so fast. The chute was unbelievable. It was a step above anything like it. So they named it the Quantum. The hang gliding world was slow to figure out that the gore count was not meaningful except for comparing canopies of the same series and manufacturer so the QS330 and the QS550 were described in terms of area. As it turned out, the optimum maximum loading was 1 lb/sq.ft. so the 330 and the 550 also represent the recomended max loading of the canopy as well. More recently, a Quantum QS440 has al.so been produced for big pilots with a gross load of up to 440 lb..

Since the test results were TOO GOOD TO BE TRUE, it seemed necessary to verify them very carefully. A very sensitive and accurate data logging system was attached to the skydiver for the test jumps. Three jumps each were conducted with a QS330 and with a LARA 325 as a control. One jump each was with a load of 225 lb., 275 lb. and 325 lb. on each canopy. In the same conditions, with the same skydiver and load, the QS330 had a 10% slower sink rate than the LARA. The end result was that the Quantum series of canopies was the most thoroughly tested and documented of hang gliding canopies. The video tape of the tests, which I call the most boring of videos showed the QS330 and the QS550 being tested for sink rate and coming down from altitude interminably. First being shot from above then from the side then from below as the videotographer sank past the Quantum reserve. The videos of the chute being load tested were much more exciting. The 330 lb. load flew out the door of the plane flying at up to 145 mph, and the Quantum chute followed, yanking the load to a sudden halt. Even from 500 ft. the extreme stability of the canopy was evident as the load decended to the ground without swinging at all. One of the tests was much more dramatic as the stop was so sudden that hardware was ripped explosively from the dummy load sending pieces of schrapnel through the canopy, destroying it. The first few tests pointed out a few changes that needed to be made to the canopy design as there were a few line breakages and rips in panels, but the final tests were 100% perfect at speeds of 135 mph.

About this time, I heard from Betty about the Quantum. She had me in mind when the canopy was designed and so she wanted to share with me her excitment about the success of the design effort. I was in a club rarer than the Catapillar Club, which is for people who have had their lives saved by a parachute when their aircraft failed. I was in the club for pilots who had aircraft failure, threw their chute, it didn't open, but they lived. I didn't want to tempt fate, so I ordered a new Quantum right away. Unfortunately, Betty's excitement didn't extend to giving me a new Quantum, so I bought it at the regular price. Soon, I also bought one for my paraglider as well.

I probably will never have to throw my parachute in an emergency again. But better to take precautions 10,000 times than to not take them when you need them. If I do throw it, I want it to open quick and come down slow. I will probably never test drive a Quantum, but I am convinced that it will do that for me.

Remember, whatever reserve you fly with, don't store it in your car trunk in the summer, get it repacked every year, and keep those rubber bands fresh.

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