Drones can be used to do a lot of good, such as finding a lost child in the woods or helping farmers monitor crops, but the federal government must create rules to ensure they operate safely, U.S. Sen. Susan Collins told federal officials at a hearing Wednesday.

Regulators must strike a balance between legitimate uses by responsible drone owners and “dangerous intrusions caused by irresponsible operators,” Collins said at the hearing on drones held by the Senate Transportation, Housing and Urban Development Appropriations Subcommittee.

The drone industry in the United States has seen explosive growth, with an estimated 700,000 drones currently in operation and another million expected to be sold this holiday season. The Federal Aviation Administration is working to establish new rules for drone operators by June 2016.

While groups representing pilots have fought for stricter rules for drones, the FAA has been viewed by many in the industry as too risk-averse.

The lack of a regulatory framework could slow development of a domestic drone manufacturing industry, which internationally is expected to grow from $4 billion to $14 billion annually over the next decade.

Collins, R-Maine, will play a key role on the issue because she is chairwoman of the Appropriations Committee’s Subcommittee on Transportation, Housing and Urban Development, one of two Senate panels with jurisdiction over new drone rules. The other is the Senate Commerce, Science and Transportation Committee.

Wednesday’s hearing focused on safety. Nobody from the industry was invited to speak.

Collins said she is particularly worried about “rogue” drones that could interfere with aircraft.

According to the FAA, there were 764 possible encounters with unmanned aircraft reported by pilots or airport personnel from November 2014 to August 2015.

One of those encounters occurred in Maine. On March 24, a radio-controlled helicopter about 8 inches long was found at the intersection of taxiways at the Portland International Jetport, according to the FAA. The drone was sitting upright and facing the runway.

The “massive” growth of the drone industry has outpaced the FAA’s ability to regulate it, Tim Canoll, president of the Air Line Pilots Association, told the committee.

He said drones are ruggedly built and carry multiple on-board cameras and batteries made of hard metal. A drone’s density is significantly greater than that of a bird, and a collision could damage windscreens and engines. He said the FAA needs to study the level of damage drones could cause should they collide with an aircraft.

Until solutions are developed, no unmanned aircraft should be allowed unrestricted access to the nation’s air space unless the operator meets the same standards as a licensed pilot, Canoll said.

NEW KIND OF PILOT

Drones are creating a level of public interest in aviation the world hasn’t seen since the Wright brothers in 1903 proved that people could build machines that fly, said Michael Huerta, administrator of the FAA.

The crux of the problem is the casual user who flies drones for recreation, he told the committee.

Drones are a new class of aircraft that have allowed a “new class of pilot” to take to the skies, Huerta said.

“The vast majority of these operators do not have the basic aviation training or experience required for pilots of traditional aircraft,” he said. “They have no knowledge that they may be flying in controlled airspace. Some may have no recognition that their actions could have serious consequences. They are simply having fun with a toy.”

He said the FAA wants to integrate drones and their operators into the national air space. Because the industry is evolving so quickly, he said, the regulatory framework must be flexible enough to respond to new technologies.

“Our goal is to provide the basic rules for operators, not identify specific technological solutions that could quickly become outdated,” he said.

The FAA last week created a task force charged with developing proposals for the registration of drones. The registration process will help build a culture of accountability and responsibility, especially for new users, Huerta said.

“This culture of accountability and responsibility will in turn help create space for the creativity, innovation and exploration that will drive this industry forward in the years and decades ahead,” he said.

The FAA currently prohibits drones from being flown for commercial purposes without a waiver. The FAA has so far granted more than 1,300 waivers nationally.

Recreational drones, which weigh less than 55 pounds, must be flown within the operator’s field of vision and below 400 feet. Drones and model aircraft are prohibited from flying within 5 miles of an airport without first obtaining permission from the control tower.