A timeline of Boeing’s ongoing 737 MAX crisis

The latest black eye for Boeing’s top-selling 737 MAX aircraft occurred in January when a cabin panel blowout forced an Alaska Airlines flight to make an emergency landing.

US regulators briefly grounded certain planes for safety checks. That’s not as severe a move as the grounding of all MAX-family jets worldwide nearly five years ago following a pair of fatal crashes.

A report released by US National Transportation Safety Board (NTSB) on Februaru 6 has confirmed that the door panel that flew off a Boeing 737 MAX 9 jet mid-flight on January 5 appeared to be missing four key bolts. The report is a preliminary one from US investigators that provided the first official look into how the frightening mishap took shape.

Lawmakers and the flying public have demanded answers to what caused the panel to flyoff a brand-new Alaska Airlines-operated jet, in what has turned into a full-blown safety and reputational crisis for Boeing.

“Whatever final conclusions are reached, Boeing is accountable for what happened. An event like this must not happen on an airplane that leaves our factory,” Boeing CEO Dave Calhoun said in a statement. “We simply must do better for our customers and their passengers.”

Here is a timeline of recent issues surrounding Boeing’s 737 MAX planes:

OCTOBER 2018: A Lion Air MAX plane crashes in Indonesia, killing all 189 people on board.

NOVEMBER 2018: The FAA and Boeing say they are evaluating the need for software or design changes to 737 MAX jets following the Lion Air crash.

MARCH 2019: An Ethiopian Airlines MAX crashes, killing all 157 people on board. China’s aviation regulator becomes the first in the world to ground the MAX, followed by others including the US Federal Aviation Administration (FAA).

APRIL 2019: The FAA forms an international team to review the safety of the 737 MAX. Boeing cuts monthly production by nearly 20 per cent.

JULY 2019: Boeing posts its largest-ever quarterly loss.

SEPTEMBER 2019: Boeing’s board of directors creates a permanent safety committee to oversee development, manufacturing and operation of its aircraft.

OCTOBER 2019: Boeing fires Kevin McAllister, the top executive of its commercial airplanes division.

DECEMBER 2020: The company fires CEO Dennis Muilenburg in the wake of the twin crashes.

JANUARY 2020: Boeing suspends 737 production, its biggest assembly-line halt in more than 20 years.

MAY 2020: Boeing resumes 737 MAX production at a “low rate.”

JUNE 2020: Boeing begins a series of long-delayed flight tests of its redesigned 737 MAX with regulators at the controls.

SEPTEMBER 2020: 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 oversight and certification.

NOVEMBER 2020: The US FAA lifts the grounding order, allowing the 737 MAX to fly again.

DECEMBER 2020: Congress passes legislation to reform how the FAA certifies new airplanes, including requiring manufacturers to disclose certain safety-critical information to the FAA.

JANUARY 2021: The European Union Aviation Safety Agency approves the MAX’s return to service in Europe.

MARCH 2021: China’s aviation regulator says major safety concerns with the MAX needed to be “properly addressed” before conducting flight tests.

APRIL 2021: Boeing halts 737 MAX deliveries after electrical problems re-ground part of the fleet.

NOVEMBER 2021: Current and former Boeing company directors reach a $237.5m settlement with shareholders to settle lawsuits over safety oversight of the 737 MAX.

OCTOBER 2022: The FAA tells Boeing that some key documents submitted as part of the certification review of the 737 MAX 7 are incomplete and others need a reassessment.

DECEMBER 2022: Congress agrees to extend a deadline for new standards for modern cockpit alerts stemming from the 2020 legislation after intense lobbying from Boeing.

APRIL 2023: Boeing pauses deliveries of some 737 MAXs to deal with a new supplier quality problem involving noncompliant fittings.

JULY 2023: Boeing’s first delivery of the 737 MAX 7 is delayed to 2024.

AUGUST 2023: Boeing identifies a new 737 MAX supplier quality problem involving improperly drilled holes on the aft pressure bulkhead.

SEPTEMBER 2023: Boeing 737 MAX deliveries fall to their lowest levels since August 2021.

DECEMBER 2023: Boeing makes its first direct delivery of a 787 Dreamliner to China since 2019, seen as a precursor to China potentially unfreezing deliveries of the 737 MAX.

JANUARY 2024: A mid-air cabin blowout compels Alaska Air to perform an emergency landing of its recently acquired 737 MAX 9 aircraft, prompting the FAA to ground 171 of these jets and initiate an investigation. The FAA also bars Boeing from increasing MAX output, but lifts the grounding of MAX-9s once inspections were completed.

FEBRUARY 2024: The US NTSB published its preliminary report on the Alaska Air incident involving a Boeing 737 MAX jet. According to the investigation, the door panel that flew off the jet mid-flight appeared to be missing four key bolts.