Boeing Co has fired Chief Executive Dennis Muilenburg following a year of intense scrutiny and industrial setbacks set off by twin fatal crashes of its 737 MAX jetliner.

Here is a timeline of events:

DEC. 20, 2019 – Boeing’s new astronaut capsule, the CST-100 Starliner, fails after liftoff to climb high enough in orbit to reach the International Space Station, cutting short a critical unmanned test mission.

DEC. 12, 2019 – Boeing abandons its goal of winning regulatory approval for the 737 MAX to resume flying in December after the U.S. Federal Aviation Administration (FAA) said the plane would not be cleared to fly before 2020

DEC. 11, 2019 – FAA chief Steve Dickson says 737 MAX will not be cleared to fly before the end of 2019

NOV. 15, 2019 – The head of the FAA tells his team to “take whatever time is needed” in their review of the 737 MAX

NOV. 11, 2019 – Boeing says it expects the FAA to issue an order approving the plane’s return to flight in December, forecasting commercial flights to resume in January.

NOV. 7, 2019 – U.S. and European regulators ask Boeing to revise documentation on its proposed 737 MAX software fix

OCT. 24, 2019 – Boeing says it still expects FAA approval to fly the 737 MAX in the fourth quarter, sending its shares higher despite a slump in quarterly profit. FAA says it will need “several weeks” for review

JULY 18, 2019 – Boeing says it has assumed regulatory approval of the 737 MAX’s return to service in the United States and other jurisdictions will begin early in the fourth quarter

JUNE 27, 2019 –  Boeing says it will take until at least September to fix a newly identified problem with software that emerged when FAA test pilots were reviewing potential failure scenarios of the flight control computer in a 737 MAX simulator.

MAY 16, 2019 – Boeing says it has completed a software update for its 737 MAX jets and is in the process of submitting a pilot training plan to the FAA

APRIL 6, 2019 – Boeing says it will cut monthly 737 MAX production by nearly 20%; U.S. and airline officials say they believe the plane could be grounded for at least two months

MARCH 13, 2019 – FAA joins other major global regulators in grounding the 737 MAX, citing evidence of similarities between the two fatal crashes

MARCH 12, 2019 – FAA says will mandate that Boeing implement design changes on the 737 MAX by April that have been in the works for months

MARCH 10, 2019 – An Ethiopian Airlines 737 MAX crashes, killing all 157 people on board. REUTERS