The drone hovered inches above the floor of the racquetball court, paused a moment, and then jumped 8 feet in the air before descending with a bump.

“Essentially, a quadcopter is a flying brick,” drone safety instructor David Iadevaia told the class gathered recently at the Oro Valley Recreation Center.

While a remote-controlled plane can glide to a stop, a quadcopter drone will drop straight down if it loses power, said Iadevaia, a retired astronomy and physics professor at Pima Community College who now runs Airborne Precision Imaging-Arizona.

Each of the half-dozen students took a turn with the drone. Some handled the controls with ease. Others jerked their bodies to the side as they tried to will the drone away from the walls.

Iadevaia was on hand to show the students how to master the manual controls, understand how the radio transmitter communicates with the drone, and learn where drones are allowed to fly.

“There are ways to be safe and there are ways to be an idiot,” Iadevaia said as he showed video clips of drones crashing into garage doors, getting caught by dogs and birds and smashing into a bride and groom as they posed for a wedding photo.

During the holiday season, the Federal Aviation Administration estimates about 800,000 drones were sold across the country.

The FAA website says drones “pose new security and privacy challenges and must be traceable in the event of an incident.”

As of Dec. 21, drone operators must register their aircraft with the FAA before flying them outside.

For drones that weigh between half a pound and 55 pounds, operators must affix the registration number to their drones and carry their registration certificate when they fly.

Registration costs $5, must be renewed every three years, and can be done online.

Drones larger than 55 pounds must be registered as traditional aircraft.

A rule already on the books prohibits hobbyists from flying unmanned aircraft higher than 400 feet or within 5 miles of an airport.

Drones have myriad uses, including targeted killings by the U.S. military and remote surveillance of the U.S.-Mexico border. But they also represent a burgeoning hobby with global appeal.

For Elijah Woodward, an aviation enthusiast who wanted to be a pilot as a kid but didn’t have the best eyesight, drones offer the chance to reach for the heavens.

“That’s good stuff,” he said with a smile as he handed over the drone’s remote control.

Two students at Wednesday’s class chatted about racing drones on the outskirts of Tucson. The mammoth retailer Amazon is planning to use drones to deliver packages. Videographers recently used drones to capture breathtaking shots of Chernobyl and the Himalayas. A local real estate agent uses drones to shoot videos and photos of properties for sale — among the first real estate businesses in the nation to get an FAA permit to do so.

Another student, Richard Egolf, 67, started flying drones last year, and calls them “excellent platforms for aerial photography.”

Egolf attaches a camera to a drone to photograph the desert plants and wildlife outside Tucson, he said after the class, adding “sunsets in Arizona from 400 feet are pretty spectacular.”

But drones also have become a nuisance, with the FAA recording about two dozen encounters in Arizona between drones and aircraft in the past year.

In Ohio, a drone operator recently spurred a brawl at a prison when the drone dropped tobacco, marijuana and heroin into the prison yard.

Egolf doesn’t see a problem with the new FAA regulations, which are “obviously a reaction to people who were being irresponsible.”

A Christmas gift of a small drone is a good way to learn about flying, he said, but large drones will require serious training.

Commercial airline pilot Paul Emmert, 58, said he hasn’t had any encounters with drones while flying for Alaska Airlines.

“But with more and more drones flying around, the safety aspect is really important,” he said.

When asked if he planned to give drones as Christmas gifts, Emmert cracked a grin and said, “No, but I’m planning on getting one, though.”

Contact Curt Prendergast at 573-4224 or cprendergast@tucson.com. On Twitter @CurtTucsonStar