Airports around the world have contacted Gatwick to learn from the drone chaos before Christmas

Gatwick and Heathrow airports have ordered military-grade equipment worth millions of pounds to try to prevent a repeat of the travel chaos caused by drones at Gatwick.

The technology will track unmanned aerial systems after the armed forces withdrew their detection equipment from the airport this week.

The military was called in last month after drones spotted round the perimeter of Gatwick — Britain’s second busiest airport — led to it closing from December 19 for three days, with 1,000 flights cancelled and the travel plans of 140,000 people disrupted. The Ministry of Defence is on standby to help if further problems arise at Gatwick.

Yesterday morning Chris Grayling, the transport secretary, hosted a meeting of police, aviation and defence chiefs to discuss lessons that