FAA forecasted that US airlines' collective traffic will grow at an average annual rate of 3.2% over the next 20 years to reach 1.57 trillion RPMs by 2032, down 15.8% from the 3.8% average annual passenger traffic growth rate predicted by the agency last year.

At its annual Aviation Forecast Conference in Washington Thursday, FAA projected that US airlines will grow passenger capacity at annual average rate of 3.1% over the next two decades, reaching 1.89 trillion ASMs by 2032. "In the near-term we see a pause in growth followed by modest increases," FAA executive director-aviation policy Nan Shellabarger told the conference.

System RPMs are projected to rise just 0.5% year-over-year in 2012, she said, adding that passenger traffic growth rates will slowly pick up in future years. The agency predicted that international passenger traffic will grow 4.2% on average per year through 2032 while domestic RPMs will increase by an average of 2.7% annually.

FAA said its baseline forecast "assumes that the economy recovers from the current downturn and suffers no major mishaps such as large oil price shocks, swings in macroeconomic policy or financial meltdowns."

FAA forecast that US airlines will carry 1 billion passengers annually by 2024, three years later than projected last year. "Growth over the next five years will be moderate, with a return to historic levels of growth only attainable in the long term," the agency stated. "This delayed trajectory represents the downward adjustments of the overall economy, here in the US and abroad, and the aviation sector's responses. One of the many factors influencing the delayed recovery is the uncertainty that surrounds the US and European economies."

FAA said it will be 2016 before US airlines return to 2007 passenger capacity levels. The agency's forecast calls for the price of oil to approach $140 per barrel by 2032. It projected "relative stability" in airline yields over the next several years.

FAA predicted that US airlines' cargo traffic will grow at an average annual rate of 4.9% over the next 20 years, led by 6% yearly growth on international routes.