FAA Orders Manual Revisions for 737 MAX Following Air Conditioning Fault
The Federal Aviation Administration has issued an airworthiness directive for Boeing 737 MAX 8 and 737-8200 aircraft to address a circuit breaker issue that could lead to excessive temperatures in the cabin and flight deck.
The decision follows concerns that if a specific circuit breaker trips, it may cause a malfunction in the air conditioning system, resulting in a rapid and uncontrollable rise in onboard temperatures.
Under the directive, operators are required to revise the Airplane Flight Manual within 30 days. The update must provide flight crews with clear operating procedures to follow in the event that the affected circuit breaker trips. The FAA stated that the directive applies to 2,119 aircraft worldwide, including 771 registered in the United States.
According to the regulator, two recent in-flight incidents were reported in which cabin temperatures increased sharply. Boeing identified the root cause as a ground wire fault within the air conditioning system.
The FAA warned that such a malfunction could lead to uncontrollable, excessively high temperatures, potentially causing injury or incapacitation of flight crew and passengers. In a worst-case scenario, this could compromise the ability to maintain safe flight and landing.
Boeing said it supports the directive and confirmed it is developing a permanent engineering solution to eliminate the possibility of the electrical fault. The manufacturer added that it expects the fix to be ready for the 737 MAX 7 and 737 MAX 10 before certification and does not anticipate any impact on the certification timeline.
Southwest Airlines, which experienced one of the reported incidents, confirmed it is in close coordination with the FAA and Boeing and has informed its flight crews about the procedures to address the specific electrical fault.
