"It is expected that this situation will increase throughout the day and tomorrow, as Ryanair's maximum profit system of leaving the minimum time between flights will cause delays," it added.
The aviation sector is struggling to recover from the pandemic, which led to mass layoffs as international travel was put on hold.
Faced with staff shortages, Amsterdam's Schiphol Airport was forced to announce earlier this month that it would be limiting traveller numbers this summer and cancelling flights.
The shortages have already caused hundreds of flights to be cancelled, while huge queues have angered travellers.
