A drone flies overhead as Russia’s Vladislav Boyarinsev competes in the Ski Jumping World Cup Large Hill event on Dec. 7, 2014. (Cornelius Poppe/AFP/Getty Images)

Federal lawmakers on Wednesday questioned whether the Federal Aviation Administration is able to cope with an influx of small, cheap drones that are endangering air traffic, saying the agency was moving too slowly to adopt safety regulations.

Citing recent reports of near-collisions between handheld drones and passenger planes, members of a House Transportation Committee panel said they were alarmed that aviation standards have not kept up with rapid technological advances that are fueling a boom in consumer drone sales.

“I’ve got a quadcopter on my Christmas list, as I suspect many people do,” said Rep. Blake Farenthold (R-Tex). But with an estimated half-million small drones sold in the United States over the past three years, he said he was worried the FAA was losing a battle to protect the national airspace. “We’re really going to have a dangerous situation,” he said.

Rep. Elizabeth Esty (D-Conn.) said she recently attended a charity event where a drone buzzed overhead. “I don’t think we can rely on the hobbyists here” to adhere to strict safety standards, she said. “All it’s going to take is one horrific accident.”

Pilots have reported a sharp increase in risky encounters with drones, including close calls at the nation’s busiest airports, according to FAA data released last month. Since June 1, commercial airlines and private pilots have alerted the FAA to at least 25 episodes in which hard-to-see drones came within a few feet of crashing into much larger aircraft.

Aerial footage recorded from a drone of a foggy Dallas sunrise Tuesday morning. (YouTube/Mike Prendergast)

Pilots described most of the rogue drones as small, camera-equipped models that have become increasingly popular with hobbyists and photographers. Although such drones generally weigh only a few pounds, aviation safety experts say they could easily trigger an accident by striking another plane’s propeller or getting sucked into a jet engine.

The FAA allows recreational drone flights as long as operators keep them below 400 feet and at least five miles away from an airport. But those guidelines are being widely flouted by drone enthusiasts, and the FAA has struggled to enforce the rules.

Peggy Gilligan, the FAA’s associate administrator for aviation safety, acknowledged the problem with rogue drones, which she attributed to untrained operators. She said the agency was conducting a public outreach campaign to educate users.

The FAA has also imposed a general prohibition on flying drones for commercial purposes while it develops safety regulations for the industry. With those regulations still years from becoming finalized, however, commercial photographers and other businesses are ignoring the FAA’s drone ban and taking to the skies anyway.

Gilligan said the agency hoped to unveil proposed regulations this month for drones weighing less than 55 pounds.

She acknowledged that it would take much longer to collect public comment and finalize the rules; other U.S. officials predicted it could take until 2017 or 2018 until they take effect. Devising regulations for larger drones that weigh more than 55 pounds is expected to take even more time.

“We all agree that that project is taking too long,” Gilligan said, adding that it “has been delayed beyond what any of us think is acceptable.”

Since June 1, pilots of passenger airlines and other aircraft have reported 25 near-collisions with small drones across the United States.

Shortly before the hearing began, the FAA announced that it had granted special permission to four companies to use drones on a limited basis for aerial surveying and inspections.

The permits are a way for the companies to sidestep the FAA’s temporary prohibition on commercial drone flights around the country until the agency can adopt a permanent set of safety standards.

Along the same lines, the FAA in September granted exemptions to six Hollywood filmmakers, allowing them to fly drones on movie sets. That precedent-setting decision was the first time the FAA had given permission to businesses to fly drones near populated areas.

In the meantime, the FAA has begun to consider special exemptions to the commercial drone ban on a case-by-case basis. Gilligan said the agency is processing more than 150 other applications from businesses seeking permission to fly drones.