Parachute Trainees Walk on Air in Wind Tunnel to Prepare for Free-Falls

The young airman had just fallen the equivalent of 32,000 feet, wind rushing by at 95 m.p.h., without a parachute.

Then he sauntered over to look at his performance on television.

Above him, another airman jumped into the stream of the vertical wind tunnel at Wright-Patterson Air Force Base.

“I got a lot more confidence here than just jumping out (of an airplane), which is what we were going to do if we didn’t get here,” said the airman, Bruce.

Covert Forces

His trainer, Master Sgt. David Davis, asked that full names not be used because many of the 53 soldiers learning to free fall in the wind tunnel are members of covert special operations forces.

When they jump into action, they likely will bail out at about 12,500 feet and silently glide toward a target before opening their parachutes at about 4,000 feet, Davis said. It is called free falling, and Davis said some jumps may be from as high as 25,000 feet.

“One minute in here is equivalent to a free fall from 12,500 feet,” he said.

Each volunteer starts with four minutes in the wind tunnel, in full jump suit and helmet, as the wind is sucked in by a 16-foot propeller turned by a 1,000-horsepower motor.

Suspended by Rope

Jumpers are suspended by a rope about 3 feet above a net covering the 12-foot opening through which the wind rushes.

“You can feel it pushing your skin and face up. I wasn’t really thinking of anything but keeping my eye on the instructor,” Bruce said.

Eagle-eyed instructors use hand signals and sometimes grab a leg or arm to keep students from becoming man-sized pinwheels--especially while they learn to grab the rip cord without starting a dangerous tumble.

“All you have to be concerned with is that your body remains symmetrical,” Davis said.

Three Days in School

Each student spends three days in ground school before five training sessions and a test during the week in the wind tunnel, Davis said. The rest of the five weeks is spent jumping out of airplanes, he said.

The wind tunnel is “a lot more cost-effective” than trying to teach a class of 50 while they are free falling out the back of an airplane for the first time, he said.

Davis is an instructor with the HALO--High Altitude, Low Opening--program at the U.S. Army John F. Kennedy Special Warfare Center and School at Ft. Bragg, N.C.

When he trained in 1979, the vertical wind tunnel was not in use to train soldiers. “So my first jump they took me up to 12,000 feet and, there you go mate, out of the airplane,” he said. “The first time I was so anxious, I wasn’t scared. The third time I got nervous.”

Now he has more than 500 free-fall jumps.

Column of Air

HALO instructors not only have to be free-fall experts, they must don bulkier flight suits and float without a rope on the column of air in the wind tunnel. The air can push a person 25 feet high, Davis said.

“That gets a little hairy up there. You feel like you’re on top of a beach ball” trying to stay on the cone of air, Davis said. “When you’re at 12,500 feet, you know you have plenty of time. In here, you know that if you get off that column of air, all you have is that concrete wall and floor to slam into.”

As a precaution, all the areas are padded. Glenn Gustafson, an aeronautical engineer who runs the tunnel for the Flight Dynamics Laboratory, said there never has been a major accident.

The 70-foot-high wind tunnel has been used for training parachutists for about five years, Davis said.

Tested Spin Control

It originally was built to test spin control on World War II airplanes, Gustafson said. As that work was transferred to the National Aeronautics and Space Administration at Langley Air Force Base in Virginia, the Wright-Patterson tunnel turned to testing parachutes and braking devices for seek-and-destroy weapons.

Parachute practice gave the wind tunnel a new lease on life, Gustafson said.

Volunteers for free-fall school must complete regular military jump school, where they learn with a static line that opens their parachute immediately after they leave the airplane, Davis said.

Used by Astronaut

An occasional general and even an astronaut have tested their skills in the wind tunnel.

Gustafson said the astronaut flew in the tunnel last November to test whether a crew using escape systems from the space shuttle could maneuver in bulky spacesuits, especially with heavy helmets.

“He was amazing” and had no problems, Gustafson said.