Michael O'Leary's landmark move at the end of last year to open the door to union recognition at Ryanair was aimed at settling simmering labour unrest. But a summer of disruption, in part the result of industrial action by pockets of its staff around Europe, illustrates the scope of challenges faced by the Irish low-cost carrier.

The IATA-CFM International agreement which opens up the maintenance market to third-party competitors was disclosed at a time when much of Europe France, in particular had embarked on vacation.