WASHINGTON, Sept 25 (Reuters) - The head of the Federal

Aviation Administration told a U.S. Senate panel on Wednesday

that Boeing ( BA ) must address a series of safety issues before

he will let them boost 737 MAX production, warning the issue

could impact company profits.

FAA Administrator Mike Whitaker capped production at 38

planes per month in January.

"They cannot grow to where they need to grow without"

making broad safety improvements in six key categories, Whitaker

said. "They don't do that, they don't grow, and if they don't

grow, they're not going be able to achieve profitability."