Ryanair Holding Plc scrapped flights for 100,000 passengers last month as operations at the discount carrier were hit by strikes in five nations together with air traffic control disruption across a swathe of Europe.

Ryanair canceled almost 550 flights in August, compared with 27 a year earlier, the Dublin-based company said in a statement Tuesday. Cockpit crews walked out on Aug. 10 in Germany, Ireland, Belgium, the Netherlands and Sweden, while controller shortages hit flights in the U.K., Germany and France.

That limited passenger growth to 5 percent, though the addition of half a million customers from the company’s new Laudamotion unit in Austria swelled overall gains to 9 percent, giving a monthly total of 13.8 million travelers.

Ryanair has begun to make headway in negotiations with pilots, who have seen their bargaining power increase following a rostering foul up last year. The carrier last week signed its first ever union contract, involving crews in Italy, and an agreement is due to be put to crews in Dublin, one of its biggest bases.

Ryanair suffered more than 1,000 flight cancellations in July, and over 1,100 in both May and June.