(Adds background throughout, details of meetings with board in second paragraph, coming meeting with FAA head)

Feb 21 (Reuters) - The head of Boeing's troubled 737 MAX program, Ed Clark, has left the planemaker, according to a memo seen by Reuters, amid intense scrutiny around its production and safety measures following a Jan. 5 mid-air panel blowout.

The changes came after Boeing's board met this week, according to a source familiar with the matter.

Boeing has been scrambling to explain and strengthen its safety procedures after the accident on a brand new Alaska Airlines 737 MAX 9 that became detached during flight. Clark oversaw the company's production facility in Renton, Washington, where the plane involved in the accident was completed.

He is being replaced by Katie Ringgold as vice president and general manager, according to the memo, which was sent to staff by Boeing Commercial Airplanes CEO Stan Deal. The memo was first reported by the Seattle Times.

The leadership changes come ahead of Boeing CEO Dave Calhoun's planned meeting with FAA Administrator Mike Whitaker next week after the top aviation regulator traveled to Renton, Washington to tour the Boeing 737 plant.

The U.S. Federal Aviation Administration grounded the MAX 9 for several weeks in January and has capped Boeing's production of the MAX while it audits the planemaker's manufacturing process.

The door panel that flew off the jet appeared to be missing four key bolts, according to a preliminary report from U.S. the U.S. National Safety Transportation Board in early February.

According to the report, the door plug in question was removed to repair rivet damage, but the NTSB has not found evidence the bolts were re-installed.

The panel is a plug in place on some 737 MAX 9s instead of an additional emergency exit. (Reporting by David Shepardson in Washington and Abhijith Ganapavaram in Bengaluru; Editing by Pooja Desai and David Gaffen)