The US Boeing Group issued a bulletin addressed to supplier companies In recent days, in which it recommended the practices to be adopted to ensure that the bolts of the aircraft's plug doors were adequately tightened. The notice was issued after several companies reported loose bolts during inspections of the 737 MAX 9 aircraft they have in their fleet.

During the inspections "we found some loose bolts on many" MAX 9s. "My question to Boeing is: what are they going to do to improve their internal quality programs?", revealed yesterday the CEO of Alaska Airlines, Ben Minicucci. FAA Administrator Mike Whitaker assured that this is not a design problem: "You need to have a quality control system that's robust enough to see if something isn't assembled correctly". 

"Ensure that work instructions are error-proof and that quality is continuously monitored, in particular the tightening requirements" of bolts, reads the bulletin revealed by the "Reuters" news agency. The document suggests that suppliers implement these provisions in work instructions, record the force applied by mechanics when fixing components, and ensure that tools used are properly calibrated. 

The note was issued on January 17, approximately two weeks after the in-flight explosion of a door on board a 737 MAX 9 aircraft operated by Alaska Airlines. The aircraft manufacturer called it an "imperative" that suppliers meet the quality requirements communicated in the bulletin. The objective is to accelerate the FAA's green light for the return to the sky of the 171 MAX 9 aircraft grounded by the authorities after the incident.

On the same topic, see also the article published by AVIONEWS.