Airline bosses are gathering in Brussels to discuss how to minimise the impact of air traffic control (ATC) strikes.
The chief executives of easyJet, Ryanair and British Airways parent company IAG are among those attending the summit organised by lobby group Airlines for Europe (A4E).
The meeting in the Belgian capital takes place amid another strike by French ATC unions.
Hundreds of flights to, from or over France were cancelled on Tuesday due to the 12th strike in the past 13 weeks.
A4E has warned that travellers face a "summer of chaos", with eight further ATC strikes announced in Italy and Portugal over the next four weeks.
It has called on the European Commission and governments to take action to reduce the impact of strikes, and wants neighbouring countries to be allowed to carry out ATC duties in air space affected by industrial disputes.
Ryanair cancelled 166 flights due to the latest French ATC strike, affecting 30,000 passengers.
The Dublin-based carrier estimated that a further 100,000 customers would suffer delays.
Kenny Jacobs, Ryanair's chief marketing officer, said: "It is time for action by the European Commission following this latest French ATC strike aimed at disrupting as many travel plans as possible.
"The frequency of these strikes, right in the middle of the holiday season, only serves to underline how urgent action is required to help reduce the impact of these strikes."
EasyJet announced 56 cancelled flights and warned further delays were expected.
It released a statement which read: "EasyJet can assure its passengers it will do everything possible to limit the inconvenience of this strike on them."