Delivery of packages by unmanned aerial vehicles would not be possible under draft regulations governing the use of the technology released by the US Federal Aviation Administration.
Requiring drone operators to obtain special pilot licences, the FAA envisions drones in the US could only be flown within the line of sight of the operator, at the maximum speed of 160km/h and only up to the altitude of 152m.
The ‘line of sight’ requirement in particular is likely to prevent many commercial applications of the unmaned aerial vehicles envisioned by the industry including Amazon’s package delivery or inspections of pipelines, power lines and crop surveying.
The FAA said in some cases the limitation could be overcome with a secondary drone spotter cooperating with the drone’s pilot.
"This rule does not deal with beyond line of sight, but does allow for the use of a visual observer to augment line of sight by the operator of the unmanned aircraft," FAA Administrator Michael Huerta said in a conference call with reporters on Sunday.
According to the draft rules, which have been ten years in the making, drones are not allowed to fly during the night and their operators are obliged keep them away from people.
The rules, which are much tougher than in many European countries, will be subject to a public consultation. The final version is expected to be released in about a year.
Commenting on the guidelines, FAA administrator Michael Huerta said the agency was not considering the use of drones for package deliveries, something online retail giant Amazon has been investing heavily over the past years.
"We are committed to realizing our vision ... and are prepared to deploy where we have the regulatory support we need," Amazon's vice president of global public policy Paul Misener told Reuters in a statement.
In Germany, for example, the first trial of drone package delivery was launched last year by logistics firm DHL testing the technology to deliver goods to residents of a remote island.
"The United States cannot afford to lag behind other countries in technological innovation because of regulatory foot-dragging," US Senator Cory Booker, a New Jersey Democrat, commented on FAA’s proposal.
Huerta said the FAA is open to discussions and expects the guidelines to evolve based on technology developments.
The rules currently also prohibit the use of drones by news-gathering companies to film footage of crowds.
Contrary to expectations, the rules don’t require drone operators to undergo regular flight training and obtain certifications equal to those needed for piloting manned planes.
The minimum age for issuing a drone operator permit has been set at 17 years. The applicant would have to pass an aeronautical knowledge test and go through examination by the Transportation Security Administration. But they would not need to undergo the medical tests or flight hours required of manned aircraft pilots.
Separately, President Barack Obama issued a memo outlining principles for government use of drones, covering such issues as privacy protections and oversight of federal drone use.