Boeing given long list of proposed fixes for 737 Max return

U.S. aviation regulators have proposed a long list of fixes to Boeing Co.’s grounded 737 Max in one of the most extensive set of requirements the agency has issued following an accident.

The Federal Aviation Administration on Monday asked for public comment on the changes it expects to require to the plane linked to two fatal crashes.

In addition to fixes specific to the system implicated in the accidents, it would mandate broad computer changes to improve reliability, add a warning light that was inoperative in the two crashes and rerouting electrical wires that don’t meet safety rules.

Boeing climbed 3.1% to $162.86, edging up after the FAA announcement. The shares fell more than half this year through last week, the worst drop on the Dow Jones Industrial Average.

The release of the proposal shows that, after 16 months of the plane’s grounding and a series of investigative reports and congressional hearings, aviation regulators are satisfied that the fixes will allow the plane to safely resume service. Flight tests of the redesigned systems by FAA were completed July 2.

The agency “has preliminarily determined that Boeing’s proposed changes to the 737 Max design, flight crew procedures and maintenance procedures effectively mitigate the airplane-related safety issues” revealed in the crashes, it said in a summary report it included with the proposal.

The FAA’s proposal for fixes and a preliminary report on its findings from its own internal investigation provides the most detailed accounting by the agency to date on what the plane’s original shortfalls were and what went wrong in the two crashes.

The actions would cost U.S. airlines about $1 million for the 73 planes registered in the country, the FAA said. The agency didn’t estimate how much it would cost to make the required changes on the several hundred jets registered in other countries and didn’t account for Boeing’s costs. The Chicago-based manufacturer may cover some of the airlines’ repair costs under warranty, FAA said.

The public has 45 days to comment on the FAA’s plans. That means the plane most likely can’t get the official go ahead to return until October at the earliest. With airlines having to retrain pilots and perform maintenance on the grounded fleet, it will take weeks or months longer before the planes begin carrying passengers.

The FAA has the authority to order such aircraft repairs without seeking public input, but federal regulations typically require such comments and allowing them helps insulate the agency against legal challenges.

The changes listed by the FAA track with those that have been discussed for months, indicating no new problems were found in the later stages of the agency’s review.

A pair of crashes—each tied to the same flawed system that malfunctioned and repeatedly dove the planes—killed 346 people less than five months apart.

The first occurred Oct. 29, 2018, in the Java Sea shortly after takeoff from Jakarta. The second was on March 10, 2019, in Ethiopia. The plane was grounded worldwide three days after the second crash.

The FAA said that a feature, known as Maneuvering Characteristics Augmentation System, had failed to meet safety requirements because it could fail with a single malfunctioning sensor and its repeated attempts to push down a plane’s nose could overpower pilots who didn’t react properly.

MCAS was installed to meet FAA safety requirements, the agency said.

In both crashes, a malfunctioning sensor that erroneously reported the planes were pointed too high began automatically and repeatedly pushing down the noses of the jets.

Boeing’s engineers assumed that pilots would know how to disable the motor driving down the nose and the procedure for doing so is taught to all 737 pilots. But both crews apparently became confused during the emergency and neither was able to do so.

The redesigned system will have multiple protections to prevent such a crash in the future.

Instead of firing repeatedly, it can only activate once in the new design. It checks data from two sensors instead of one. And its power to dive a plane has been reduced.

In addition, there will be training for pilots and documentation of how the system works to help crews prepare for failures in the future. Boeing is also revising eight emergency procedures in its flight manuals for the plane, FAA said.

Originally, pilots weren’t told about the system. Both the company and the FAA didn’t realize it could pose a danger.

The accidents also prompted a reexamination of the 737 Max’s flight-control computer, which led to a redesign of that system as well in an attempt to make it more resilient against failure.

Finalizing new pilot training will be done separately by an FAA panel that will also give the public a chance to comment on the changes.