The U.S. Federal Aviation Administration briefly halted flights at Miami International and nearby airports around noon on Thursday following a power outage at Miami's Terminal Radar Approach Control, a spokeswoman said.
Most of the systems have since resumed functioning, spokeswoman Kathleen Bergen said in a statement. Air traffic control is allowing flights to land with spacing of 30 miles between them, compared with normal spacing between three and five miles, she said.
The outage affected a facility overseeing flights from central Florida to the Caribbean.
Planes in Miami as well as those across the United States bound for the area briefly could not depart, while those in the air were told to fly in a holding pattern until it was safe to land in South Florida.
Earlier, the agency said in an online advisory that pilots in the air could expect delays of up to 30 minutes. As of 1:15 PM Eastern (1715 GMT), flight tracking website FlightAware.com showed 14 planes in Miami International and seven destined for the airport were delayed.
Bergen said the FAA was investigating the cause of the outage.