**A Major Infrastructure Challenge at Paris-Orly** The Fédération Nationale de l’Aviation et de ses Métiers (FNAM) has raised concerns about the operational impact of the upcoming renovation of runway 4 (06/24) at Paris-Orly Airport. Scheduled from 10 August to 17 December 2026, the complete refurbishment will force the airport to operate with reduced capacity for over four months. According to FNAM estimates, around 3,000 flights may be cancelled, rescheduled, or transferred to Paris-Charles de Gaulle during this period, particularly affecting the peak summer traffic. **What the Works Entail** Runway 4, measuring 3,650 metres, is undergoing a full overhaul including pavement repair, reconfiguration of taxiway nodes W42-W43, renovation of taxiway W47, and updates to lighting and structures. This is part of Groupe ADP’s long-term modernisation plan for Orly. The runway had reached the end of its service life and required urgent intervention. After the recent treatment of runways 2 and 3, runway 4 is the last of the three main runways to undergo major works in 2026. **Operational Consequences for Airlines and Passengers** Airlines operating heavily at Orly, such as low-cost carrier Transavia, will face significant scheduling constraints during the high season. Adjustments may include timetable changes, frequency reductions, or transfers to CDG. Sébastien Justum, Deputy Secretary General of Air France-KLM (Transavia’s parent company), stressed the need for close coordination: “Airlines will have to manage an accumulation of major constraints this summer. Each of these issues requires extremely close coordination among all air transport stakeholders and special attention from state services.” **Relevance for ATPL and ATC Students** This real-world case illustrates how airport infrastructure projects directly affect flight planning, slot allocation, and air traffic flow management. For ATPL students, it highlights the operational ripple effects of reduced runway capacity—such as increased holding times, alternate airport planning, and fuel considerations. For ATC trainees, it demonstrates the need for flexible sequencing, coordination with adjacent sectors, and communication with airlines to minimise disruptions. Understanding such events is crucial for managing real-world traffic scenarios and anticipating delays. **Looking Ahead** Groupe ADP has yet to publish detailed mitigation measures, but further communications are expected in the coming weeks. Passengers are advised to check flight status regularly and allow extra time, especially between August and September. This project underscores the delicate balance between modernising ageing infrastructure and maintaining operational capacity during peak periods. The coming months will reveal whether promised coordination can limit passenger disruption.