Staff shortages at Gatwick’s control tower led to at least 100 flight cancellations on Sunday.
Separately, British Airways reportedly cancelled up to 300 flights to and from Heathrow, Gatwick and London City airport from Friday, estimated to be the busiest day of the year for departures, for an unspecified reason.
The latest in a round of staffing issues at the Gatwick control tower disrupted 15,000 passengers. Similar problems occurred a year ago and in June.
Air traffic control provider Nats reportedly imposed restrictions on take offs and landings “in order to maintain safety”, The Independent reported.
At least 64 EasyJet flights flights were affected alongside BA, Norwegian, Vueling and Wizz Air.
Flight analytics firm Cirium calculated that 53 departing flights were cancelled due to ATC staffing shortages, equating to 13% of all scheduled departures at Gatwick on Sunday.
A further 52 arrivals into the airport were cancelled, equating to 12% of all scheduled arrivals.
Ryanair said: “UK Nats staff shortages caused multiple flight delays and cancellations at Gatwick airport yesterday (Sunday).
“This is the latest in a long line of cock ups by UK Nats, which has yet again disrupted multiple flights and thousands of passengers at Gatwick.”
A Nats spokesperson told the newspaper: “These restrictions are due to short-notice staff absence at the air traffic control tower and in addition to existing restrictions already in place due to adverse weather across UK and Europe.
“We apologise sincerely for the inconvenience and are working closely with the airport and airlines to try and keep disruption to a minimum.”
An EasyJet spokesperson added: “Nats air-traffic control staffing shortages at Gatwick led to a significantly reduced flow rate being imposed on all airlines today (Sunday) which is resulting in flights to and from Gatwick airport being subject to disruption including some cancellations.
“We are extremely disappointed that customers are once again being impacted by this and while this is outside of our control, we are sorry for the inconvenience caused.
“We are doing all possible to minimise the impact of the disruption and have notified those on cancelled flights of their options to rebook or receive a refund and are providing hotel accommodation and meals where required.
BA grounded evening flights to and from Bordeaux and Jersey on top of previous cancellations unrelated to the air-traffic control issues.
A spokesperson for Gatwick said on Sunday: “Due to short-notice absence in the air-traffic control tower, temporary restrictions have been put in place today, in addition to existing restrictions in place due to adverse weather across UK and Europe. These may result in some delays and cancellations.
“London Gatwick apologises to any passengers impacted by these restrictions. Please contact your airline for more information.”
Cirium also found that a total of 427 flights due to depart from UK airports were cancelled last week – 2% of all scheduled departures – duet poor weather and ATC staffing shortages at Gatwick
The total was up 223% on the previous week, which saw only 132 cancelled departures from UK airports.
Heathrow saw the largest number of departing cancellations during the week (165), followed by Gatwick (87) and London City (36)
A further 408 arrivals into UK airports were cancelled during the same seven day period – equating to 2% of all scheduled arrivals