The United States will mandate that Boeing implement design changes by April that have been in the works for months for the 737 MAX 8 fleet after a fatal crash in October, but said the plane was airworthy and did not need to be grounded after a second crash on Sunday.
An Ethiopian Airlines 737 MAX 8 bound for Nairobi crashed minutes after take-off on Sunday, killing all 157 aboard and raising questions about the safety of the new variant of the industry workhorse, one of which also crashed in Indonesia in October, killing 189 people.
Boeing confirmed the Federal Aviation Administration's announcement late Monday that it will deploy a software upgrade across the 737 MAX 8 fleet "in the coming weeks" as pressure mounted.
Two US senators called the fleet's immediate grounding and a rising number of airlines said they would voluntarily ground their fleets.
The company confirmed it had for several months "been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer".
Boeing did not reference Sunday's Ethiopian Airlines crash in connection to the software upgrade. The statement did express the company's condolences to the relatives of the 157 people who died, however.
The FAA said the changes will "provide reduced reliance on procedures associated with required pilot memory items".
The FAA also said Boeing will "update training requirements and flight crew manuals to go with the design change" to an automated protection system called the Maneuvering Characteristics Augmentation System or MCAS.
US Transportation Secretary Elaine Chao told reporters regulators would not hesitate to act if they find a safety issue.
"If the FAA identifies an issue that affects safety, the department will take immediate and appropriate action," Chao told reporters.
"I want people to be assured that we take these incidents, these accidents very seriously," she said.
Boeing's top executive told employees on Monday he was confident in the safety of the US manufacturer's top-selling 737 MAX aircraft. The company added that it was "still early" in the Ethiopian Airlines investigation.
Reuters and other media outlets have reported that Boeing has for months planned design changes after the Lion Air crash in Indonesia but the FAA notice was the first public confirmation.
