Boeing Co generated more than $3 billion in free cash flow in the final quarter of 2022, allowing the company to post positive full-year free cash flow for the first time since 2018, its chief executive said on Wednesday.

The U.S.-based plane manufacturer had forecast about $2.5 billion in free cash flow for the fourth quarter. Boeing had previously predicted between $1.5 billion and $2 billion for all of 2022.

In a Wednesday morning email to employees, which was made available to Reuters, Boeing CEO Dave Calhoun called the transition to positive cash flow "an important metric in our recovery."

Boeing has said it plans to deliver up to 450 737 MAX narrowbody aircraft and 70 to 80 widebody 787 Dreamliners in 2023. The company previously stated it would generate $3 billion to $5 billion in free cash flow in 2023.

"While we have made meaningful progress, challenges remain and we have more work ahead to drive stability in our operations and within the supply chain," Calhoun said in the email.