Gatwick's runway has reopened after drones caused the airport to shut down for more than a day.
The airport, the UK's second busiest, said 837 flights were scheduled but there were delays and cancellations.
Boss Chris Woodroofe said "mitigating measures" from the government and military had given him "confidence to reopen".
The drone operator is still at large and police said it was possible they were an environmental activist.
The airport is expected to be "back to normal" by the end of Saturday.