Gatwick's runway is now open and flights are arriving and departing, after drone activity in its airspace caused a complete shutdown.
Knock-on delays and cancellations to flights are still expected. Passengers are strongly advised to check the status of flights before arriving at the airport.
Stewart Wingate, chief executive officer of Gatwick Airport, said: 'These events obviously highlight a wider strategic challenge for aviation in this country which we need to address together with speed - the aviation industry, Government and all the other relevant authorities.
'It cannot be right that drones can close a vital part of our national infrastructure in this way. This is obviously a relatively new technology and we need to think through together the right solutions to make sure it cannot happen again.'
He added that the drone activity was 'highly targeted' and 'has been designed to close the airport and bring maximum disruption in the run up to Christmas'.
Over 120,000 passengers have had their journeys disrupted by the situation.
The police have yet to catch those responsible.
Nearly 50 reports of a drone being flown illegally around the airport have been received since mid-evening on Wednesday.
Detective Chief Superintendent Jason Tingley, from Sussex Police specialist crime command, said: 'In addition to the searches that are taking place on and around the airfield, we are deploying a number of tactical options to detect and counter these drone activities and bring this to a safe conclusion. Extra officers have been brought in to support the operation.
'Our assessment, based upon the information that we have available to us, is that this incident is not terrorism-related.'
Earlier this year the government brought in laws to restrict all drones from flying within 1 kilometre of airport boundaries.