MODEL AIRPLANES : Youngsters Learn to Build and Fly Their Creations : The class at the Thousand Oaks Teen Center is led by a 77-year-old retired aeronautics engineer.

For an hour, the gym at the Thousand Oaks Teen Center was an airfield. Young, wanna-be pilots patiently wound the rubber-band-driven propellers of their paper airplanes and gave them a final inspection.

“Clear the field! Test flights are over,” yelled John Van Hamersveld. The first airplane took off and circled the gym slowly and silently for nine seconds.

“Boy, look at that go,” Van Hamersveld marveled. To the 77-year-old retired aeronautics engineer, it was beauty in motion.

Van Hamersveld teaches children how to build model airplanes--and fly them. To the aviation whiz, there is no point in building them if you can’t fly them. And fly them right.

For the last three years at the Teen Center, he has taught a class for youngsters 12 to 15 years old. A Thousand Oaks resident, he volunteers his teaching time; it’s a mission of sorts.

“I’m sick and tired of seeing kids running around doing nothing,” he said. “This country needs real talented people to compete in the world.”

Learning aeronautics by constructing and flying a paper airplane is just the kind of know-how that can put a kid on track for a technical career, he thinks. And in today’s highly technical world, that’s where it’s at, he says.

“Pilots built models as young boys,” he said.

During his six-week class, Van Hamersveld limits the group to six or seven. This time, as usual, they are all boys. They learn how to put together three model airplanes from kits, starting with a simple one-foot wingspan paper model and moving on to a more complicated two-foot cabin plane. The balsa wood planes are powered by rubber bands.

Each boy is assigned a box with a knife, razor, glue, sand block, masking tape and pins. They learn quickly that Van Hamersveld insists on perfection. Wood must be cut precisely, paper glued neatly. If the plane isn’t balanced properly, it won’t fly right.

On this day, the boys are working on the Piper Cub. The landing gear is crafted from bent wire, and to help them get the angles correct, Van Hamersveld fashions a mold for them to bend their wires around. Meanwhile, as they crowd his work area, he explains why the wheels on airplanes are turned in.

“I teach the fundamentals of aerodynamics,” he said of his two-hour class. He has a no-nonsense approach that doesn’t leave room for clowning around. But these boys live and talk aviation. Van Hamersveld spins out phrases like “the center of lift,” and they soak it up.

“I’ve been building plastic models since I was four,” said T. J. Thomas, 12. His collection numbers 50 or 60. “I like the older prop designs.” T. J., like the other boys, wants to be a pilot.

Van Hamersveld learned to fly in college, where he earned an engineering degree, specializing in aeronautics and metallurgy. He was working for an aviation company in 1942 when he contracted polio. He recovered, but he lost the use of his legs and the ability to fly. He turned to sailing instead.

For the last 50 years, he has worked for a number of aerospace companies, the last being Northrop’s former Ventura County division. These days his heart is in model airplanes. He figures he has built about 100. He flies remote control planes and is working on the design of an electrically powered type.

Building models is more popular than ever, he said, citing the growth of the Academy of Model Aeronautics, with its 100,000 young and adult members. The organization sponsors meets, and he competes.

Always at his side is his wife, Betsy, who knows a good bit about model construction. He runs the class from a wheelchair while she helps the boys individually.

“If they sat home and put these together, they wouldn’t know how to fly them,” she said. “Kids get discouraged when it doesn’t fly and gets wrecked.”

The biggest problem that the boys have is tackling the model without reading and following the instructions. Sometimes the class reveals serious reading problems, Van Hamersveld said.

On this day the boys are wired. They’re all buzzing about the contest in the gym during the last half of the class. The kid who can keep his plane aloft the longest wins a kit for a Piper Cub model.

The planes they are flying are basic paper models with a one-foot wingspan. The propeller must be wound to a precise degree of tension, Van Hamersveld instructs. And in the right direction. One boy made that mistake and saw his plane fizzle to the ground in a second.

Van Hamersveld shows them how to bend the propeller slightly to make the plane fly in circles. For the planes that take off with the nose too high, he takes a pinch of clay and packs it onto the nose for added weight.

“Of course, that reduces the flying time,” he advises the boys.

Until all the adjustments are made, the planes smack into the walls or the ceiling. One boy’s model landed in the rafters, and another’s sailed through the basketball hoop only to become lodged in the basket.

After the trial flights are over, the boys are timed on three flights. Andy Johnson, 13, takes the prize with the best total time of 30.78 seconds and the best single flight of almost 12 seconds.

“They have a lot of fun doing this,” Van Hamersveld said. “And it uses the brain.”

* WHERE AND WHEN

John Van Hamersveld’s model airplane class meets weekly for two hours at the Thousand Oaks Teen Center. Cost is $10. Call the center at 494-5156 for information about the next series of classes.

For supplies and information about model airplane clubs, here are a few places to call: Marty’s Hobbies in Thousand Oaks, 497-3664; Red Baron Model Hobbies in Camarillo, 482-0250; and Blue Max in Oxnard, 483-0664.