A near miss with a personal drone forced a Shuttle America flight to pull up while on final approach to land at LaGuardia Airport in New York City earlier this year. It wasn't the first such incident. The U.S. Federal Aviation Administration currently receives about 60 reports from pilots every month that represent potential drone sightings. No one knows exactly the type or extent of damage that a collision with a small drone could cause to a jet airliner's engine or airframe, but the agency plans to research that possibility in the next fiscal year. Meanwhile technologies and policies that could deter such collisions remain up in the air.

The current prevention tactic is to stop repeat offenders. The FAA works with local law enforcement to contact drone operators who carry out an “unauthorized [unmanned aerial system] operation” to educate them about flight safety regulations. The agency can also tack on civil penalties for “careless or reckless operation” of drones.

But the FAA needs to do more to avert collisions than educate citizens, says Ben Berman, a Boeing 737 pilot for a major U.S. airline. “Most near-collision courses are going to be misses,” he explains. “But if we roll the dice on near collisions with drones enough times a year, eventually you'll come up snake eyes.”

Small drones—classified by the FAA as weighing less than 55 pounds—cannot carry the relatively heavy traffic collision and avoidance system used by larger aircraft to track the locations of nearby planes. As an alternative, Berman, a former chief investigator for the National Transportation Safety Board, thinks drone manufacturers should program their craft to avoid flying above certain altitudes or into restricted airspace. The FAA has also mentioned such “geo-fencing” software updates as a potential short-term fix but does not require them for small drone makers.

One best-selling-drone manufacturer has already taken such steps. DJI, a company based in Shenzhen, China, makes the world's most popular small drones, with its Phantom models costing about $1,000 apiece. Since 2014, DJI has pushed out drone firmware updates to clearly show operators the restricted airspaces around airports, Washington, D.C., or national borders. Operators who ignore the software warnings about restricted airspace and try flying forward will find their drones simply refusing to move. “It's like flying into an invisible wall,” DJI's Michael Perry says.

Several other tactics could be hovering just over the horizon. In February the FAA proposed rules for small drones that include speed and altitude restrictions and access limits to airspace where manned planes typically fly. Such rules could be finalized as early as 2016. On the technology side, NASA has been working with industry partners to develop an unmanned air traffic system that could track small drones at low altitudes. The space agency also has tested a detect-and-avoid system for larger unmanned aircraft such as its Ikhana drone, a civilian version of the military's Predator drone. Such technology could eventually scale down for smaller drones.

These solutions have become more incumbent as growing numbers of drones find their way into the hands of ordinary consumers. This year China exported 160,000 civilian drones worth $120 million from January to May, according to the Xinhua News Agency. “We're in the process of going from these very niche hobby products to mass consumer products,” Perry says. “Many consumers just entering this space don't know the rules and regulations in the way that model aircraft hobbyists used to.”