Andy Pasztor

WASHINGTON—Widespread use of commercial drones is likely to take significantly longer than many proponents of the budding industry anticipate, according to U.S. and Canadian aviation regulators.

That blunt message was delivered by high-ranking aviation safety officials from the U.S., Canada and the United Nations last week to an industry conference here.

At a time when champions of unmanned aircraft are escalating efforts to obtain federal approvals—with some U.S. lawmakers also demanding swift regulatory action—the latest comments highlight the extent of the hurdles that remain.

Last week’s session underscored the reluctance of regulators across North America and other regions to quickly give the green light to extensive drone flights, based on safety concerns. A representative of the International Civil Aviation Organization, an arm of the U.N., expressed similar sentiments during the panel sponsored by the Air Line Pilots Association, a major union.

Granting regulatory approval to operate remotely piloted vehicles among manned aircraft is “not going to be as soon as some people tend to think,” John Hickey, the No. 2 safety official at the Federal Aviation Administration, told the gathering.

“We’re still many years away from what you would see as safe integration in the very busiest airspace,” according to Mr. Hickey. “We will not allow [drones] to come into the system until we are completely sure they are safe.”

Congress has mandated that by the fall of 2015, the FAA institute a comprehensive plan to safely integrate manned and unmanned aircraft in U.S. skies.

Mr. Hickey’s comments reiterated that the FAA considers itself obligated to formulate a plan by that deadline, rather than start allowing widespread drone operations by then.

Initial U.S. rules covering the smallest unmanned aircraft aren’t likely to become final until late next year. Rules for larger, more-capable models are likely to come years later.

During the same conference session, Martin Ely, who heads civil aviation regulation for Transport Canada, the government’s regulatory department, said sweeping integration of drones into national and international airspace “is probably a long way away.”

Mr. Ely said Transport Canada last year approved nearly 1,000 permits authorizing drone operations in designated areas, segregated from common airspace.

That is three times the number approved a year earlier, he said.

But Mr. Ely said the industry hasn’t yet developed the technology drones need to see and avoid other aircraft—safety features considered essential before operations can be approved in normal airspace.

Mitchell Fox, head of ICAO’s flight operations office, predicted that international standards for certifying drones, pilots and widespread operations are at least four years away. And they won’t be binding on regulators or operators. “The incremental approach is essential,” Mr. Fox said.

To ease mounting pressure from drone advocates, the FAA is allowing case-by-case approvals for a modest number of specific uses of small, low-flying drones. Industry proponents, however, have been clamoring for expanded approvals.

In June, the U.S. Transportation Department’s inspector general issued a report concluding that “the magnitude of unresolved safety and privacy issues will prevent” the FAA from meeting the timetable imposed by Congress. The report said the FAA has so many challenges to resolve that it isn’t clear when remotely controlled aircraft can be safely integrated into U.S. airspace.

In addition to technical issues regarding navigation, systems reliability and emergency procedures if communication links go down, federal officials have been struggling with privacy considerations.

FAA officials remain leery of being responsible for regulating privacy, and the White House and other agencies are debating where in government such matters should be decided.

Last fall, when federal aviation regulators released their first overall plan to eventually integrate drones into U.S. airspace, they riled critics seeking greater attention to privacy protections.

At the time, the FAA laid out nearly 100 pages of specific technical and procedural principles intended to ensure safe design and operation of domestic drones—an early step toward what proponents project could be routine flights by tens of thousands of government and commercial drones by 2025.

But the plan was less encompassing and detailed regarding privacy issues.

The FAA acknowledged the agency wasn’t expert in that area, and largely reverted to existing state and federal laws for privacy safeguards when drones start flying at six test sites.

Recognizing that “there is substantial debate and difference of opinion” about whether the test sites will raise new privacy concerns, the FAA opted to require operators to collect written plans for each drone’s use and retention of data, among other rules.

Over the years, the FAA has approved many drone operations by law-enforcement and other public agencies, but all of those were and remain restricted to areas strictly cordoned off by regulations from all other air traffic. Commercial users, by contrast, are seeking to integrate drones into the broader national airspace.

In June, BP PLC signed a five-year contract to use drones at its oil operations in Alaska, the first large-scale, government-approved commercial use of unmanned aircraft in the U.S.

http://online.wsj.com/articles/widespread-commercial-drone-flights-years-away-regulators-1407697835