Tens of thousands of passengers are set to be affected as major airlines cancelled more than 1,000 flights on Friday ahead of a walkout by French air traffic controllers.
France's aviation authority DGAC has warned of "severe" disruption and asked carriers to halve their flight schedules, with the strikes also likely to disrupt flights passing over French airspace.
The action is due to run from 6am on Friday 16 September until 6am on Saturday 17 September.
France’s main union of air traffic controllers, the SNCTA, called the one-day strike to demand higher pay as inflation skyrockets and to call for more workers to be hired in the coming years.
It's the latest blow for holidaymakers, who have suffered from widespread delays and cancellations throughout the travel chaos of the spring and summer.
So which airlines are affected and what does this mean for your travel plans?
Watch: Airline refunds: What are your rights as a consumer?
Europe’s largest budget airline Ryanair (RYA.IR) has grounded 420 flights, affecting 80,000 passengers.
Most of the cancellations were on routes that neither land in, or take off from, France, the carrier said.
Many Ryanair departures from UK airports to Spain, Portugal, Italy and Switzerland normally traverse French airspace.
The Ireland-based airline called on the European Union to mandate overflights when controllers strike.
Ryanair said in a statement: "It is inexplicable that thousands of European citizens/visitors will have their travel plans unfairly disrupted by yet another French ATC [air-traffic control] strike and that flights which overfly France are disrupted by French ATC strikes yet domestic French flights are protected by minimum service laws.
"Ryanair is once again calling for immediate EU action to prevent these French ATC strikes disrupting the travel plans of thousands of European citizens/visitors."
Affected customers have been contacted and advised of their options, the airline said. Under European air passengers’ rights rules, travellers are entitled to be flown as soon as possible on any available flight.
EasyJet (EZJ.L) has cancelled 76 flights so far on Friday as more than half of the airline’s normal services cross French territory.
Europe's second largest budget airline said the cancellations were at the request of French authorities.
"While this is outside of our control, we would like to apologise to our customers for any inconvenience they may experience," it said in a statement.
The French flag carrier said it would run just 45% of its short-haul flights due to the strikes, and 90% of long-haul. That represents nearly 60% of total operations.
Air France (AF.PA) has also cautioned that "delays and last minute cancellations cannot be ruled out".
British Airways (BA) has cancelled 22 flights, but warned there could also be some delays on Friday.
Outside of the air traffic control strikes, BA passengers will also be affected by flight cancellations on Monday for the Queen's state funeral.
The International Consolidated Airlines Group (IAG.L) owned airline will ground 100 flights on Monday 19 September as part of Heathrow's funeral-related cancellations.
Britain's busiest airport, Heathrow has announced it will pause flights on Monday 19 September to ensure the skies over London fall quiet during Queen Elizabeth's state funeral.
The west London hub said that all take-offs and landings on Monday will be delayed for 15 minutes before and after the two-minute silence at the end of the funeral.
After that, there will be no arrivals between 13:45 BST (British Summer Time) and 14:20 BST during the procession of the hearse, and no departures between 15:03 BST and 16:45 BST for the ceremonial procession via the Long Walk to Windsor Castle.
Departures will be reduced between 16:45 BST and 21:00 BST, to support the committal service at St George's Chapel.
Additionally flights will also be diverted around Windsor Castle "to minimise noise during the private family service and interment", Heathrow said.
It added that the changes will affect about 15% of its schedule, which it said was "equivalent to a moderate weather event".
There will also be flight cancellations, including 100 British Airways flights and four Virgin Atlantic flights.
In total, around 200 flights are expected to be grounded from the airport, the vast majority on Monday.
Around 35,000 passengers flying on Sunday, Monday and Tuesday are set to be affected.
The Civil Aviation Authority (CAA) has issued guidance which means that passengers whose flights are cancelled or badly delayed on 19 September due to the changes will not legally be entitled to financial compensation, as these are likely to be deemed extraordinary circumstances.
But airlines are offering customers refunds and re-bookings.