Britain’s second-busiest airport has re-opened after all flights were suspended for two hours “due to an air traffic control systems issue”.
The closure of Gatwick’s runway, caused by a problem related to the control tower, began at 5.08pm.
It re-opened at 7pm, however the airport warned travellers on Wednesday evening and Thursday to check the status of their flight.
A spokesman for the airport said: “As we move back into full operations, we are likely to see some delays and further cancellations this evening.
“We apologise to passengers who have been affected and are aiming to operate a full schedule of flights tomorrow.
“We continue to advise all passengers travelling tonight or tomorrow to check the status of their flight with their airline before travelling to the airport.”
Meanwhile, a spokeswoman for the airport said a total of 26 flights had been diverted and eight cancelled as of 7.30pm, but warned the number could change.
A spokeswoman for NATS, the air traffic services provider for London’s Stansted and Luton airports, said flights had mainly been diverted to those locations.
Gatwick has the busiest runway in the world, with a take-off or landing every 80 seconds at peak times.
Many arriving aircraft were diverted.
A British Airways arrival from Tenerife is currently on the ground at Stansted. Another BA plane, inbound from Ibiza, touched down at Bournemouth, while a Verona arrival is at Heathrow.
Gatwick is the biggest base for easyJet, which in a normal day operates as many as 400 flights to and from the Sussex airport.
The airline’s diversions included services from Montpellier and Seville which landed at Luton, and from Krakow which arrived in Stansted.
The flight crew are hoping they can fly to Gatwick, but the queues of arrivals and departures are formidable.
An easyJet statement read: “Due to an earlier IT issue affecting all flights departing and arriving at London Gatwick Airport we expect delays and possible further disruption.
“Although outside of our control, we’re very sorry for any inconvenience this may cause.”
The airline also warned passengers they will not get any cash compensation: “The disruption is beyond our control and is considered an extraordinary circumstance.”
Disruption will continue well into the evening. The final wave of early evening departures from Gatwick is in disarray, with many flights cancelled and others severely delayed.
Norwegian appears to have cancelled flights to Helsinki, Gothenburg and Bergen, while Vueling has axed its evening flight from Paris Charles de Gaulle.
Although passengers do not get cash compensation, they are entitled to meals and, if necessary, accommodation until they can be flown to their destinations.
Shortly before Christmas, Gatwick airport was closed for 33 hours, disrupting the plans of 160,000 passengers, because of unauthorised drone activity.