(Reuters) -Boeing CEO Dave Calhoun will step down by the end of the year, following the planemaker's ongoing safety crisis with its 737 MAX jets that was exacerbated by a January mid-air panel blowout.

U.S. regulators briefly grounded certain planes for safety checks following the blowout, a move less severe than the grounding of all MAX-family jets worldwide nearly five years ago following a pair of fatal crashes.

Here is a timeline of recent issues surrounding Boeing's 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 U.S. Federal Aviation Administration.

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

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 U.S. 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 U.S. 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 $237.5 million 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 non-compliant 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 U.S. National Transportation Safety Board (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.

MARCH 2024:

** The FAA's 737 MAX production audit finds multiple instances where Boeing and Spirit AeroSystems allegedly failed to comply with manufacturing quality control requirements. This comes days after Boeing said it was in preliminary talks to buy Spirit.

** The ongoing crisis may mean Boeing will need more time to hit key financial targets for coming years, its CFO warns.

** Airbus clinches orders for 65 jets from two of Boeing's key Asian customers, Japan Airlines and Korean Air.

** The U.S. planemaker says CEO Dave Calhoun will step down and announces that Stan Deal, Boeing Commercial Airplanes President and CEO, will be succeeded by Stephanie Pope.

(Reporting by David Gaffen and Nathan Gomes; Editing by Leslie Adler, Maju Samuel, Devika Syamnath and Saumyadeb Chakrabarty)