In March 2017, the Federal Aviation Administration (FAA) released its annual aerospace forecast, which now includes projections for unmanned aerial vehicles (UAV), commonly called drones or unmanned aerial systems (UAS). The FAA anticipates that between 2016 and 2021, the number of commercial drones will increase at an average annual growth rate of 58.6 percent, while hobbyist fleets will triple in size. According to the FAA, we could see as many as 6.12 million drones in the sky by 2021.
The forecast includes a caveat that projections are difficult "given the dynamic, quickly-evolving market" and regulatory uncertainty. In other words, growth will either be large or huge. While there were 42,000 commercial drones in the US at the end of 2016, the FAA said that by 2021 commercial UAS fleets could range from 442,000 to as many as 1.62 million.
Even the FAA's high estimate is conservative, since commercial drones are still a fledgling industry. It has been less than a year since regulators loosened the rules so that some commercial pilots no longer have to seek special exemptions. So far, 20,000 pilots have already obtained commercial drone licenses, and the agency expects 10 to 20 times more registered pilots by 2021.