European airports are in the middle of another busy summer as passenger numbers globally recover to pre-pandemic levels.
Airlines have said they are ready to avoid a repeat of last year's travel chaos, after strikes and staff shortages forced them to cancel thousands of flights to avoid long queues at major airports.
But air traffic control strikes, which have caused airlines to demand protections for overflights, and ongoing wage talks by airport and airline staff could bring about further disruptions.
Here is a summary of recent developments:
BRITAIN
Heathrow Airport security workers on June 23 called off 31 days of strikes planned at Britain's busiest hub. Over 2,000 staff accepted an improved pay offer for a rise of between 15.5% and 17.5%.
At Birmingham Airport, around 100 security officers and terminal technicians will begin continuous strike action from July 18. The strikes will severely impact the airport's security and terminal maintenance, leading to flight delays, the Unite union said.
Unite has also said that workers who aid passengers with mobility challenges at Glasgow Airport will take two 24-hour strikes on July 6 and July 11.
FRANCE
Air traffic controller (ATC) strikes in France have led to delays and limited flights across the country, causing more air space congestion in Europe.
Most recently, French aviation regulator asked carriers to cancel a third of their flights from the Paris-Orly airport on June 6 due to a planned ATC strike. It also asked them to reduce flights by 20% at Lyon, Marseille, Nice, Toulouse, Bordeaux and Nantes, and urged passengers to postpone trips if possible.
On June 6, Ryanair said it had to cancel 400 flights due to the 36-hour strike, most of them overflights not going to France.
ITALY
Italy's air traffic control company ENAV told Reuters there would be no strikes in the Italian air transport sector between July 27 and Sept. 5 due to a summer exemption provided for in the industry regulations.
SPAIN
Pilots at Iberia Regional Air Nostrum, who had been striking every Monday and Friday since Feb. 27, went on a daily indefinite strike from June 6 amid a pay dispute. As of July 4, Iberia said on its website that flights could be affected and offered flexible fares for some passenger travelling until July 6 on routes operated by Air Nostrum.
Air Europa pilots in Spain also went on a two-week strike on June 19.
Spain has said it expects to receive more tourists in the summer of 2023 than before the COVID-19 pandemic.
SWEDEN
The Swedish Transport Workers' Union on June 30 withdrew the strike and blockade by airport controllers, planned to start on July 3, after reaching a new surveillance and security agreement.
SWITZERLAND
Geneva Airport reached a deal with public service staff on June 30 to end a strike over pay, after it saw its air traffic halted for around four hours on the same morning. The striking workers included security and emergency staff.
(Compiled by Tiago Brandao, Pierre John Felcenloben, Antonis Triantafyllou and Romolo Tosiani; Editing by Milla Nissi)
