Flights still cannot depart or land using the main runway while the issue is being dealt with, but a back-up runway is being used.
A spokesman for Gatwick Airport said: “While the aircraft is being inspected and while the runway is being inspected there are no flights departing or arriving at Gatwick.”
The Toronto-bound Air Canada Rouge flight left the airport about 1.15pm today, but was quickly forced to land again.
In an update at 3.30pm, a Gatwick spokesman said a back-up runway was being used while the main runway remains shut.
About 12 planes have so far been forced to land at other airports, but that figure is expected to rise as the day goes on.
Travellers are encouraged to check with their airline for information about their flights.