There were flight delays on Sunday afternoon at Houston's Hobby Airport after the electricity went out in the control tower.
The outage caused equipment to fail, putting extra pressure on air traffic controllers trying to maximize safety.
They kept a number of flights circling the airport for a while early in the afternoon until technicians were able to restore normal electricity service.
At first, it looked like it might take hours to restore power, but the electricity was back on just a couple of hours after the outage began.
The Federal Aviation Administration is investigating the outage, but offered no possible explanations by Sunday evening.