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:
Heathrow Airport security workers on 23 June 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 18 July. 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 6 July and 11 July.
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 6 June 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 6 June, Ryanair said it had to cancel 400 flights due to the 36-hour strike, most of them overflights not going to France.
Italy's air traffic control company, ENAV, told Reuters there would be no strikes in the Italian air transport sector between 27 July and 5 September due to a summer exemption provided for in the industry regulations.
Pilots at Iberia Regional Air Nostrum, who had been striking every Monday and Friday since 27 February, went on a daily indefinite strike from 6 June amid a pay dispute. As of 4 July, Iberia said on its website that flights could be affected and offered flexible fares for some passenger travelling until 6 July on routes operated by Air Nostrum.
Air Europa pilots in Spain also went on a two-week strike on 19 June.
Spain has said it expects to receive more tourists in the summer of 2023 than before the COVID-19 pandemic.
The Swedish Transport Workers' Union on 30 June withdrew the strike and blockade by airport controllers, planned to start on 3 July, after reaching a new surveillance and security agreement.
Geneva Airport reached a deal with public service staff on 30 June 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.