Look out below: Researchers use GA to test parachutes

Gary Peek and Jean Potvin have enjoyed skydiving for more than two decades. These St. Louis skydivers spend nearly every weekend jumping out of airplanes for reasons most other skydivers cite: “the sense of freedom and adventure … at all the different altitudes,” Peek said.

Peek also has been a pilot since 1988, seven years after taking introductory flights in both a Cessna and a glider. While not flying as often as he skydives, Peek has a passion for both that led to his becoming an expert in the properties of parachutes—so much so that in 1996 he and Potvin launched a program to research parachutes’ design, inflation, drift, weight capacity, and how strong they need to be when they open.

The findings of the Parks College Parachute Research Group (PCPRG), which is affiliated with St. Louis University (SLU), are not filed away as mere theory. The U.S. military and defense contractors hire PCPRG to conduct the studies, often implementing the information when planning the drops of supplies to combat troops in Afghanistan. PCPRG also conducts research to help the Interior Department’s Bureau of Land Management fight forest fires.

Because of the dangers of shoulder-launched rockets, U.S. aircraft in Afghanistan fly higher to safely drop food, water, ammunition, and even vehicles, Peek explained. And, because soldiers “can be in danger when retrieving supplies,” he said, drops “have to be precise—within 50 meters.” Technology allows some parachute drops to be GPS-guided so that they land where programmed, Peek continued.

“Precision air drop is very important to the military right now. We do very basic research to support the military,” Peek said. “[Parachutes] can take a big hit. Some parachute landings can be hard. A parachute doesn’t necessarily mean a soft landing—just getting the person or the cargo to the ground safely. … We test things that are used by the military to drop cargo. We use aircraft as a vehicle to push loads out, just as the military does in Afghanistan: They have supplies on pallets, go up in a C-130 and push that stuff out.”

Peek also is a skydiving instructor who flies recreational jumpers. For his research, though, Peek and his PCPRG colleagues—principally Potvin, an SLU physics professor—handle their test drops on scheduled skydiving flights over two area skydiving fields. They mount on the parachutes what Peek calls 100-pound steel “tubs” containing electronic instrumentation that records the parachutes’ opening forces and descent rates.

“We use the information to help validate the mathematical model on parachute inflation,” Peek explained. While the two conduct fewer tests than they used to—every few weeks in the summer—“we’re still using the data we collected years ago to improve the mathematical model,” he added.

Sometimes, Peek and Potvin are the only ones in the airplane besides the pilot. Peek usually sports a helmet-mounted camera to photograph and film the drops to study later.

Watch Potvin’s test drop, filmed by Peek.

Asked what contribution he believes general aviation and his research group make to national defense, Peek said, “It’s the general information they need to manufacture equipment that’ll be useful in war. You start out with basic research to see what is possible. We’re the very-basic-research-type folks. We push 100-pound things out of GA planes. At [the U.S. Army’s Yuma Proving Ground in Wellton, Arizona], they push 10,000-pound things out of a C-130. What we do costs far less money. You can do experiments with small-scale things before you try it with large-scale things.

“We can take a small GA aircraft and maybe gain some information that’ll help the people who supply the military. This is ‘GA serves America,’ because it serves the troops. It’s allowing a local group of researchers to provide important information to the military. When I saw [promotions for the GA Serves America campaign], I thought, ‘Yes, GA really is serving America!’” —By Hillel Kuttler