Three flights were diverted following a possible drone sighting at Gatwick on Sunday.
EasyJet flights from Barcelona and Amsterdam were diverted to Stansted together with a British Airways flight from Heraklion.
They all landed at Gatwick more than 90 minutes after their scheduled arrival time, the BBC reported.
Gatwick said it had investigated an “unconfirmed sighting of an object” outside its exclusion zone.
A spokeswoman confirmed an Aer Lingus pilot made the initial report.
The airport added: “Following a full assessment, the airport has remained fully operational throughout.”
A suspected drone closed Gatwick for 33 hours in December, disrupting about 140,000 passengers.
