FAA issues Emergency Airworthiness Directive for Boeing 737 MAX

The Federal Aviation Administration (FAA) of the United States has issued an Emergency Airworthiness Directive for the Boeing 737 MAX 8 and MAX 9 aircraft types, effective immediately.

This comes less than 24 hours after the manufacturer Boeing had already sent an Operations Manual Bulletin (OMB) to all 737 MAX operators, alerting them of potential issues with the AOA (Angle of Attack) display.

Investigators had found significant evidence that the crash of Lion Air flight J610 last week was likely caused by problems with this AOA display.

This emergency AD was prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer. This condition, if not addressed, could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain.Federal Aviation Administration

The Emergency Airworthiness Directive affects all 219 so-far delivered airplanes of the Boeing 737 MAX family and directly applies to all 45 US-registered aircraft of this type.

An explanation by the FAA on what an EAD is: “An Emergency AD is issued when an unsafe condition exists that requires immediate action by an owner/operator. The intent of an Emergency AD is to rapidly correct an urgent safety of flight situation.”

Boeing introduced the 737 MAX 8 to commercial service in May 2017 with Malindo Air, a Malaysian subsidiary of Lion Air. More than 4,700 737 MAX have been ordered in total, making it one of the most popular airliners.