Budget airline Ryanair has listed dozens of flights which it is cancelling in order to cope with a strain on crew availability over the next six weeks.
The carrier admits that its punctuality statistics have suffered over the first half of September, dropping to less than 80%.
While Ryanair attributes this partly to air traffic control capacity, weather-related disruption and industrial action, it acknowledges that a nine-month transition period in its crew leave allocation schedule is having a detrimental effect.
It expects to cancel around 40 or 50 flights each day until the end of the summer season in late October, amounting to some 2,000 services in total.
Ryanair says the crew leave change means it is having to deal with "increased holiday allocations" arising from the April-December transition interval, which has generated a "backlog" of leave.
The new leave schedule will coincide with the calendar year, rather than the April-March financial year.
Ryanair says the "tighter" crewing, as well as other adverse effects, have reduced its punctuality from 90% to an "unacceptable" 80% over the first two weeks of September. The changes will enable it to provide additional reserve aircraft to restore punctuality.
It stresses that the flight cancellations amount to less than 2% of its daily operations.