A French regional airline has grounded four of its ATR turboprop aircraft following multiple reports from pilots of suspected fumes leaking into cockpits and cabins, leading to symptoms such as migraines during flights. Among the planes grounded is one used by Airbus for shuttle flights between its factories in northwestern and southern France.

Air Corsica, which operates a fleet of 14 aircraft including seven ATR turboprops, took the precautionary measure in recent weeks while Airbus and engine manufacturer Pratt & Whitney investigate the issue. The affected turboprops are relatively new, introduced to Air Corsica’s operations in 2022 and equipped with Pratt & Whitney’s more fuel-efficient engines.

Pilots had reported detecting odors linked to potential toxic-fume events, prompting concerns over air quality within the aircraft cabins. These "fume events" typically occur when engine oil escapes past seals into compressor chambers, where it is exposed to high temperatures and releases harmful vapors that can enter the aircraft’s ventilation system. The turboprops in question employ bleed air systems, drawing unfiltered, compressed air directly from the engines into the cabin.

While Air Corsica has temporarily removed the four turboprops from service, it continues to operate Airbus shuttle flights using other aircraft in its fleet. The airline stated it is working closely with ATR, Airbus, and Pratt & Whitney to determine the cause of the issues affecting the air conditioning systems on these planes but noted that no definitive technical source has been identified to date.

ATR, the manufacturer behind the aircraft and a joint venture owned equally by Airbus and Italy’s Leonardo, confirmed that investigations are ongoing. The company emphasized that its aircraft are designed to meet established regulatory safety standards. One of the affected turboprops is currently undergoing testing at ATR’s facility in Toulouse, France, to assist in pinpointing the origin of the reported fumes.

The Pratt & Whitney engines fitted to these ATR models have become standard on recent turboprop deliveries and are used by several operators worldwide, including FedEx and India’s IndiGo. It remains unclear whether the fume incidents are specific to Air Corsica’s fleet or indicative of a broader, systemic issue with the aircraft design or the new engines.

Spokespersons for Airbus and Pratt & Whitney declined to provide comments on the investigation or the reported incidents. The matter continues to be closely monitored by both the airline and manufacturers as they seek to ensure the safety and well-being of crew and passengers.