The pilot began to pedal to the steady beat of a metronome. The filmy wings of the 100-pound helicopter swept upward and began to gracefully rotate. A light breeze blew toward the dozens of eager but patient parents, journalists and other spectators who had packed into a University of Maryland gym Wednesday morning.

It was as if everyone was standing in Kitty Hawk, waiting to see the Wright brothers take off for the first time. The blades whirled around and around, about 14 times a minute.

A first try. A second try.

But the human-powered helicopter never left the ground.

The crowd thinned. TV crews packed up and left. Finally, the dean of the school’s engineering college grabbed a microphone and announced a three-hour break so the students could tinker with the cockpit back at the shop.

“It’s engineering. I’m sorry. It happens,” said Darryll Pines, who has taught at U-Md. for more than 15 years and became dean of its A. James Clark School of Engineering in 2009.

More than 30 years ago, the American Helicopter Society International challenged engineers to create a human-powered helicopter that could reach an altitude of at least three meters and hover for at least 60 seconds. In 1980, Sikorsky Aircraft promised $20,000 to the winner.

So far, no one has succeeded and claimed what’s now called the Sikorsky Award. There have been attempts: In 1989, students at Cal Poly San Luis Obispo built a helicopter that hovered for 7.1 seconds. In 1994, students at Nihon University in Japan flew a helicopter for 19.46 seconds.

In December 2008, Pines held a meeting with students and faculty to announce that the Maryland school would take on the elusive challenge. Soon after, Sikorsky upped the prize to $250,000.

For the next year, a team of 50 students researched past attempts, sketched out ideas and tested small-scale models. They settled on a design similar to the one used in Japan: a lightweight X-shaped frame with a set of rotor blades at each point, and the pilot suspended in a cockpit in the middle.

Last year, the students studied the extreme ground effects of hovering and decided that the closer they kept to the ground, the more suspension help their helicopter would get.

“It’s like when you hold your hand in front of a fan,” said Mor Gilad, 28, an aerospace master’s degree student. The closer your hand gets to the fan, the harder the air pressure pushes against it.

The students began constructing and testing segments of the craft, using balsa wood, foam, Mylar, carbon fiber and other lightweight materials. They also recruited potential pilots — small, athletic types with lots of patience.

The students decided they wanted to fly before commencement, which is next week, and booked a small gym in the Comcast Center. Last week, they began assembling and testing the helicopter, named Gamera, after the gigantic flying turtle in 1970s Japanese monster films.

Here’s how Gamera was supposed to work Wednesday morning: The pilot, a 107-pound female student who is a competitive cyclist, would climb into the cockpit. She’d pedal hand and foot cranks at a steady pace, winding up the yellow rope attached to pulleys that turn the rotor blades. Once she reached 17 to 18 rotations per minute, Gamera would lift off.

“The hard part is finding the right acceleration,” said Judy Wexler, 24, a biology major from Bethesda who responded to a flier advertising for a pilot. “If you go too quickly, you can break something. . . .Too slowly, you waste energy.”

After the break, the students and a smaller crowd returned for another round of test flights. Wexler had reached more than 16 rotations per minute late Wednesday; the team called it a day. Testing is to resume at 11 a.m. Thursday.

“If we even get off the ground at all, we’ll be number three,” said Brandon Bush, 29, an aerospace doctoral student. “We just have to get off the ground.”

“I’m convinced that we can do it,” Pines said. “To me this is . . .inspiring our kids, showing them that they can be the next aviation pioneers. Just like the Wright brothers.”