The Federal Aviation Administration on Wednesday issued an airworthiness directive covering all Boeing (BA) 737 Max 8 and 737-8200 aircraft to address an electrical issue that could trigger excessive heat in the cabin and cockpit.
The directive requires airlines to update flight manuals within 30 days to include specific procedures for crews to follow if a particular circuit breaker trips and causes a malfunction in the air conditioning system. The FAA said the order applies to 2,119 aircraft globally, including 771 registered in the United States.
The action follows two recent in-flight events in which onboard temperatures rose sharply. According to Boeing (BA), the problem stems from a faulty ground wire in the air conditioning system.
The FAA warned that a malfunction could result in “an uncontrollable, excessively high temperature,” potentially leading to injury or incapacitation of crew members or passengers and jeopardizing the ability to safely operate and land the aircraft.
Boeing (BA) said it supports the FAA’s directive, which formalizes guidance the company issued to operators last month.
“We are advancing an engineering solution to eliminate the possibility of this electrical fault,” the company said.
Boeing (BA) added that it expects a permanent fix for the 737 Max 7 and 737 Max 10 models to be in place before those variants receive certification and said it does not expect the issue to delay the approval timeline.
Southwest Airlines (LUV), which experienced one of the reported incidents, said it is coordinating closely with both Boeing (BA) and the FAA and has informed its flight crews of the procedures required to address the specific electrical problem.