Aer Lingus is preparing for a wave of summer disruption that could affect nearly 23,000 passengers, as maintenance delays force the airline to cancel and adjust hundreds of flights during its busiest season.

The carrier has warned it may cancel up to 2% of its scheduled flights this summer, with the impact spread across approximately 430 services. The changes come at a critical time, with the majority of its more than 12 million annual passengers travelling between April and October.

Behind the disruption is a growing issue within the global aviation maintenance sector. Repairs identified during routine inspections are taking longer than expected, largely due to supply chain shortages affecting parts and servicing capacity.

According to industry sources, around 120 flights are expected to be directly impacted by delays in aircraft body maintenance, while a further 30 flights could be affected by additional technical checks.

The disruption extends beyond cancellations. The airline is also expected to consolidate services on routes with lower demand, potentially leading to around 280 further schedule adjustments and affecting an estimated 15,000 passengers.

Flight consolidation is a standard industry practice, allowing airlines to combine passenger loads onto fewer services when demand is lower than expected. However, when combined with maintenance-related cancellations, the overall effect becomes more visible to travellers.

Aer Lingus has said it is working to minimise disruption, with plans to rebook most affected passengers onto alternative flights on the same day where possible.

The airline also moved to clarify that the issue is unrelated to fuel supply concerns linked to tensions in the Strait of Hormuz, despite wider uncertainty in the aviation sector following geopolitical developments.

Even so, the situation highlights how operational pressures – from maintenance delays to supply chain constraints – are increasingly shaping airline schedules. For passengers, it adds another layer of uncertainty to summer travel, where even routine adjustments can have a significant ripple effect across busy networks.

Industry insiders note that disruptions of this scale are not unusual during peak season, but the combination of maintenance delays and broader market pressures is making them more visible – and more closely watched – than in previous years.