Sometimes when I’m asleep, I know I’m dreaming. Then I look around for a cliff or rooftop to leap from. If I jump from high places in my dreams, I don’t fall. I fly.

According to Greek legend, Icarus flew on wings his father made for him. Later on, Leonard DaVinci drew pictures of people-powered planes with movable wings that were too heavy to flap.

The flying dream — and the dream of flying — just won’t go away.

This year we mark the 100th anniversary of the short, happy flight of Orville Wright at Kitty Hawk, N.C.

Airplanes have grown gigantic since then. The wingspan of the biggest commercial planes exceeds in length Orville’s first flight.

But the dream of moments aloft — and alone — in space continue.

Since the Wright brothers, there have been fantasies of flying cars and one-person flying platforms. In the 1950s, True magazine foresaw the dawning of an “age of skycycles.”

Current dreams of intimate flight center on air taxis that carry a handful of passengers. In his book “Free Flight: Inventing the Future of Aviation,” James Fallows says that people could be flagging down such craft at the local airport within a few years.

For that to happen, though, small airports will need the electronic capabilities of the big commercial hubs — at a lower price.

That’s why Dave Downing, Kansas University professor of aerospace engineering, is researching ways to make autopiloted landings economical and safe at small airports.

NASA is driving the small-airport, small-plane research. Today’s large airport system is almost saturated, yet the Federal Aviation Administration expects air traffic to double by the year 2010.

“Currently, we have about 500 airports that all the airlines go to,” Downing says. “Ten times that number are not being used for scheduled flights because the airlines can’t guarantee you’ll be able to arrive.”

One reason is that many small airports are ill-equipped for landings in bad weather. Downing’s group is addressing the issue by harnessing off-the-shelf hardware and custom-designed software to make guidance equipment both for ground installations and cockpits. The technology would enable planes that are approaching small airports in bad weather to find their way to what Downing calls “highways in the sky.”

Once a plane is on a “highway,” the pilot will let the technology take over until the runway comes into view.

Downing estimates that if his guidance equipment works, the runways at a small airport could be outfitted for less than $300,000. That’s good news for a state like Kansas, which has about 140 airports.

Today, it costs about $1.5 million to instrument just one runway.

Poet Robert Frost wrote, “Something there is that doesn’t love a wall.” Gravity is an invisible wall that humans obviously don’t love.

Like Larry Walters, we yearn to rise above it all.