On Thursday evening, the Federal Aviation Administration (FAA) said Boeing must inspect cabin pressure switches for thousands of its 737 jets worldwide that could lead to pilots becoming incapacitated, according to Reuters.
FAA's directive requires Boeing to conduct tests on all 737 series aircraft. There are more than 9,300 worldwide and 2,500 in the US. Inspecting cabin pressure switches will further ensure there's enough air to breathe as planes climb altitude.
The directive comes as three 737, all different series, last September, failed pressure switch tests. Defective switches could result in cabin altitude warning systems not activating above 10,000 feet, which would pose a safety risk to pilots and passengers. Dangerously low oxygen levels result in asphyxiation, then death.