Older passenger planes must get more frequent safety checks for a hidden valve problem

US aviation regulators are ordering new, more frequent safety checks for all ATR42 and ATR72 passenger planes. This means mechanics will have to test a specific valve more often to prevent a hidden failure.

Airlines operating these planes will now face higher maintenance costs and more downtime for inspections. The change addresses a risk where a critical valve could fail without anyone knowing, leading to potential safety issues. This kind of hidden failure is a known problem in aviation, and regulators often respond by increasing inspection frequency.