LAS VEGAS: As military spending shrinks, makers of unmanned aircraft are looking to civilian customers to pick up the slack — but getting ready to fly drones in civilian airspace is a big technological and regulatory challenge.

On Tuesday, acting Federal Aviation Administrator Michael Huerta became the first FAA chief to address the annual conference of the Association for Unmanned Vehicle Systems International (AUVSI). Huerta’s choice of venue was a milestone in itself, and his remarks were relentlessly upbeat about fully integrating drones in US domestic air traffic, known as the National Airspace System — even though the agency has already missed a Congressional deadline to get test sites up and running. Asked point-blank by one reporter what happens if UAVs don’t meet safety standards on time, Huerta replied, “I’m not going to speculate on hypotheticals that we won’t get there, because I’m quite confident we will.”

A NASA researcher working on the technological challenges was somewhat less sanguine. “This is happening and it’s happening quickly,” said Jay Shively at a panel at AUVSI on Monday. “We need to be ready for it — and we’re not ready for it.”

The datalinks, the bandwidth, the sense-and-avoid systems to prevent collisions, all need work. To get the rules and regulations in place by September 2015, as Congress requires, Shively sighed, “we probably had to have all the research done five years ago.”

The speaker who immediately followed Huerta Tuesday morning was sobering, as well. Leslie Cary of the International Civil Aviation Organization, a former FAA air traffic controller herself, said that ICAO had just approved global standards for “remotely piloted aircraft” that will go into effective this November, but “they’ll be just the tip of what will eventually become the complete regulatory framework.” A guidance manual is scheduled in 2014 and more complete regulations in 2016 to 2018. The date for the full panoply of international regulations to operate remotely piloted aircraft across “all classes of airspace”? 2028.

“It will usually take at least one decade to try to change an article of the convention, if not longer,” explained Cary, referring to the Convention on International Civil Aviation, informally known as the Chicago Convention, that governs the ICAO. “Every member of the [ICAO’s] UAS study group has been disconcerted by the obstacles presented by the convention,” she said, “[although] every one of the obstacles that we have encountered – so far, at least — we have overcome.”

As just one small example, Article 29 of the treaty requires every aircraft to have various certificates, licenses, and a logbook carried on board — physically improbable if not impossible for an unmanned aircraft. There are difficulties defining drones in legal terms so the rules don’t encompass model aircraft as well: Technically, said Cary, “model aircraft are unmanned aircraft, [but] we do not want to be regulating them.” More substantively, while ICAO is currently working on rules for what it insistently calls “remotely piloted” aircraft, it is well behind the industry in considering autonomous aircraft that fly themselves without having constant contact with a human operator on the ground.

The FAA, as befits the aviation agency of the world’s leading maker and user of drones, is further along. This year, Huerta boasted, the FAA consolidated oversight of unmanned air systems issues in a single UAS Integration Office. The agency has automated applications to use unmanned aircraft, with the average time for approval down to sixty days. That time’s much less for emergency applications, like January’s use of a drone to scout an oil tanker’s path through the ice to the fuel-starved Alaskan town of Nome. And the FAA will soon issue a request for proposals to manage the six drone test sites mandated by Congress — admittedly a bit behind Congress’s timeline to do so.

“There’s a lot of work that needs to be done to move UAS integration forward,” Huerta said, “but I’m very, very optimistic we will get there.”