WASHINGTON (Reuters) - The head of the Federal Aviation Administration told a U.S. House subcommittee Tuesday that safety culture improvements at Boeing ( BA ) may take three to five years to complete.

"It is not a six month program -- it is a three-year to five-year program," FAA Administrator Mike Whitaker said, adding he has spoken to Boeing ( BA ) CEO Kelly Ortberg and the company's board of directors about the need for safety culture reforms. He said Boeing ( BA ) has made significant improvement in the short term. "On culture it is a long-term project."