March 28 (Reuters) - The new head of Boeing's ( BA )

troubled commercial airplane unit said the planemaker faces a

"pivotal moment" as it works to boost quality and address

significant concerns from regulators and airline customers after

a panel flew off a 737 MAX 9 jet in January.

"This is a pivotal moment for us, and we have serious work

ahead to build trust and improve our operations," said Stephanie

Pope, who was named president and CEO of Boeing Commercial

Airplanes on Monday, in an email to employees on Wednesday seen

by Reuters.

Pope was named chief operating officer in December and

retains the title after holding a wide range of prior jobs at

Boeing ( BA ).

On Monday, Boeing ( BA ) CEO Dave Calhoun announced he would leave

by the end of the year, while the company's long-time head of

commercial airplanes, Stan Deal, retired effectively immediately

and the board chair Larry Kellner stepped down and was replaced

as chair by director Steve Mollenkopf.

GE CEO Larry Culp, who has been touted by industry

executive analysts as a possible replacement for Calhoun, said

at an event in New York he was fully focused on GE Aerospace and

would return to its headquarters in Ohio. "There's no better

business. There's no better job," Culp said.

He said Boeing's ( BA ) board would be focused on leadership

qualities in its CEO search. "This is a big company going

through tremendous challenge right now," Culp said, saying the

planemaker must be thinking about long-term product and

corporate strategy. "It won't be enough to get through the

challenges of 2024."

Boeing ( BA ) has come under intense criticism since a door plug

panel tore off a new Alaska Airlines 737 MAX 9 jet at

16,000 feet.

In the aftermath of the incident, the FAA grounded the MAX 9

for several weeks, barred Boeing ( BA ) from increasing the MAX

production rate and ordered it to develop a comprehensive plan

to address "systemic quality-control issues" within 90 days.

Boeing ( BA ) production has fallen below the maximum 38 MAX planes

per month the FAA is allowing. The Justice Department has opened

a criminal investigation into the MAX 9 incident.

"Our path forward is clear. We will put safety and quality

above all else in order to meet and exceed the expectations of

our regulators, customers, flying public and each other," Pope

said.

She said over next couple of weeks, she "will be spending my

time meeting and engaging with our team as we enhance and

implement our safety and quality improvement plan."

FAA Administrator Mike Whitaker said earlier the agency and

Boeing ( BA ) hope by the end of March to define the milestones the

manufacturer must meet.