US aviation authorities are poised as early as Wednesday to lift a grounding order here on Boeing Co's BA.N 737 MAX, a long-delayed major step in a crisis caused by fatal crashes in Ethiopia and Indonesia just five months apart in 2018 and 2019.
The disasters killed 346 people, slashed Boeing's profit, prompted lawsuits and investigations, including an active criminal probe by the US Department of Justice.
Here is a timeline of events surrounding the 737 MAX:
MARCH 8 - The 737 MAX gains US Federal Aviation Administration (FAA) certification.
MAY 22 - The 737 MAX enters commercial service on Lion Air subsidiary Malindo Air.
OCT. 29 - A Lion Air 737 MAX plane crashes in Indonesia, killing all 189 people on board.
NOV. 13 - FAA, Boeing say they are evaluating the need for software or design changes to 737 MAX jets following the Lion Air crash.
NOV. 30 - Boeing weighs plans for a software upgrade for its 737 MAX in six to eight weeks that would help address a scenario faced by crew of Indonesia's Lion Air.
MARCH 10 - An Ethiopian Airlines 737 MAX crashes, killing all 157 people on board.
MARCH 12 - FAA says will mandate that Boeing implement design changes on the 737 MAX by April that have been in the works for months.
MARCH 13 - FAA joins other major global regulators in grounding the 737 MAX, citing evidence of similarities between the two fatal crashes.
APRIL 3 - The FAA says it is forming an international team to review the safety of the now-grounded 737 MAX that will be headed by a formal top US safety official.
APRIL 6 - Boeing says it will cut monthly 737 MAX production by nearly 20%; US and airline officials say they believe the plane could be grounded for at least two months.
APRIL 24 - Boeing abandons its 2019 financial outlook, halts share buybacks and says lowered production due to the 737 MAX grounding has cost it at least $1 billion so far.
MAY 5 - Boeing did not tell US regulators for more than a year that it inadvertently made an alarm alerting pilots to a mismatch of flight data optional on the 737 MAX, instead of standard as on earlier 737s.
JUNE 17 - Boeing executives take turns apologizing for the loss of life in two 737 MAX crashes and pledge to apply lessons of the crisis to future planes.
JULY 24 - Boeing posts its largest-ever quarterly loss due to the spiraling cost of resolving issues with its 737 MAX.
SEPT. 25 - Boeing's board of directors creates a new permanent safety committee to oversee development, manufacturing and operation of its aircraft and services.
OCT. 22 - Boeing fires Kevin McAllister, the top executive of its commercial airplanes division, marking the first high-level departure since the two fatal crashes.
DEC. 12 - Boeing abandons its goal of winning regulatory approval for the 737 MAX to resume flying in December after the FAA said the plane would not be cleared to fly before 2020.
DEC. 16 - Boeing says it will suspend 737 production in January, its biggest assembly-line halt in more than 20 years, as fallout from two fatal crashes of the now-grounded aircraft drags on.
DEC. 23 - Boeing fires Chief Executive Dennis Muilenburg following a year of intense scrutiny and industrial setbacks set off by twin fatal crashes of the 737 MAX.
MARCH 9 - Ethiopian investigators single out faulty systems on a 737 MAX plane in an interim report on the 2019 Ethiopian Airlines crash, piling pressure on the US jetmaker on the eve of the disaster's anniversary.
MARCH 11 - Boeing is freezing new hiring and overtime except in certain critical areas to preserve cash, as the coronavirus outbreak compounds the MAX fallout.
- Boeing plans to separate 737 MAX wiring bundles, flagged by regulators as potentially dangerous, before the jet returns to service.
MAY 27 - Boeing says it has resumed 737 MAX production at a "low rate", after halting production in January.
JUNE 16 - US senators introduce legislation to strengthen FAA oversight of aircraft certification.
JUNE 17 - FAA chief Steve Dickson acknowledged Boeing and the US air safety agency both made mistakes on the 737 MAX.
JUNE 29 - Boeing begins a series of long-delayed flight tests of its redesigned 737 MAX with regulators at the controls.
JULY 7 - Boeing has reached settlement agreements in more than 90% of the wrongful death claims filed in federal court after the 2018 Lion Air 737 MAX crash in Indonesia that killed all 189 people on board.
SEPT. 16 - An 18-month investigation by a US House of Representatives panel finds Boeing failed in its design and development of the MAX as well as its transparency with the FAA, and that the FAA failed in its oversight and certification.
SEPT. 28 - The leaders of the US House Committee on Transportation and Infrastructure introduce bipartisan legislation to reform the FAA's aircraft certification process.
SEPT. 30 - FAA Chief Steve Dickson conducts a nearly two-hour evaluation flight at the controls of a Boeing 737 MAX.
OCT. 6 - The FAA issues a draft report on revised training procedures for the 737 MAX.
OCT. 18 - American Airlines Group AAL.O says it plans to return 737 MAX jets to service for passenger flights by the end of this year.
NOV. 9 - The FAA says it is in the final stages of reviewing proposed changes to the 737 MAX, with sources telling Reuters the FAA was set to lift its grounding order as early as Nov. 18.