WASHINGTON, March 19 (Reuters) - The head of the U.S.

Federal Aviation Administration said Boeing ( BA ) must improve

safety culture and address quality issues before the agency will

allow the planemaker to boost 737 MAX production.

The FAA in late January took the unprecedented step of

telling Boeing ( BA ) it would not allow the company to expand 737 MAX

production in the wake of a mid-air emergency on an Alaska

Airlines jet earlier in the month.

FAA Administrator Mike Whitaker told Reuters in an interview

on Tuesday that the agency has not begun discussions yet with

Boeing ( BA ) about hiking 737 production, and said the agency will

only permit an increase when Boeing ( BA ) is "running a quality system

safely."

Whitaker said he has the tools to hold Boeing ( BA ) "accountable

and fully intend to use them."

Boeing ( BA ) did not immediately comment.

Whitaker said Boeing ( BA ) is allowed to produce 38 of the 737

planes per month, but actual current production "is lower than

that"; he did not elaborate.

Boeing's ( BA ) chief financial officer, Brian West, said last

month that the planemaker's

first-half output

of 737 planes would be less than 38 per month, but in the

second half said he expected it would "move toward that 38 per

month, but it will be dictated" by the FAA.

The FAA's Whitaker said the timeline on when Boeing ( BA ) will

be allowed to boost the 737 MAX production rate will depend on

"how effectively they can implement these changes in the safety

culture and bring their quality levels up to where they need to

be."

The Justice Department has opened a

criminal probe

into the January mid-air 737 MAX 9 cabin panel blowout.

On Feb. 28, Whitaker said Boeing ( BA ) must develop a

comprehensive plan to address

"systemic quality-control issues"

within 90 days and set milestones.

"This is a long-term endeavor -- it takes a long time to

change culture," Whitaker said on Tuesday. "They certainly have

it within their capabilities to do that.

"I don't want to give the impression that this is a

90-day fix and then we move on," he added.

Separately, Whitaker spoke over the weekend with United

Airlines CEO Scott Kirby about a series of recent safety

incidents, including a plane that lost a panel on Friday.

Kirby told customers on Monday the airline is reviewing

recent safety incidents and using insights to update employee

safety training and procedures.

Kirby "knows we're going to be engaging a little more

closely with them as we look into these," Whitaker said.

United declined comment.