The Federal Aviation Administration has ordered operators of all Boeing 737 aircraft to conduct an inspection to repair potential cockpit air pressure switches.
The companies are required to perform frequent pressure switch tests and, if necessary, replace them. The order covers 2,502 aircraft registered in the United States and 9,315 worldwide.
The order was issued after an operator of that model reported in September that the two pressure switches had failed during testing of three different models of that aircraft.
The management said that the failure of the two switches could lead to deactivation of the cockpit pressure warning system, which normally works if the altitude exceeds ten thousand feet, a level at which oxygen is very little.
Cockpits are designed to have air pressure not to exceed atmospheric pressure at 8,000 feet.
Boeing said it is adhering to the FAA’s guidance, which has not been reported. Any malfunction of the two pressure switches in flight.
The administration stated that the tests must be carried out within 2,000 flight hours since the last pressure switches were tested in the cockpit or within 90 days of the order being issued.
Boeing initially reviewed the problem, including the expected failure rate of the two switches, and found that they did not pose any safety risk.
Boeing declined to Disclosure of the failure rate.
A subsequent investigation led the FAA and Boeing to determine in May that “the failure rate of both switches is much greater than initially thought, and therefore a safety issue.”
The administration added that it “does not have enough information yet to be able to determine the reason for the unexpectedly high rate of failure.”
The order includes all 737 models, including the Max, But it has nothing to do with any other issue related to Max’s return to service last November.
