TCRA officials attributed the slide to rising air fares.
"Fares have been rising steadily for the past two years, and we know there is a direct relationship between fares and the number of passengers using the Airport," Melissa Thomas, TCRA's director of marketing and air service development, said in a prepared release. "Much of the increase has to do with rising fuel costs, fewer seats available for sale and lack of low-fare competition in the market."
The number of charter passengers using general aviation aircraft was also down more than 35 percent during the first quarter, according to TCRA.
TCRA officials are hoping that new Allegiant Air low-fare service to Orlando-Sanford, scheduled to begin in mid-May, should have a positive impact on passenger numbers in coming months.
Ridership at both Knoxville's McGhee-Tyson Airport and Chattanooga's Metropolitan Airport has risen since Allegiant began offering flights. In March, passenger levels at McGhee-Tyson Airport grew 8.8 percent over March 2006. The Chattanooga Metropolitan Airport saw passenger boardings grow by 19 percent in the first quarter.
"The additional air service competition has also lowered fares to many of Chattanooga travelers' top destinations," Mike Landguth, president and CEO of the Chattanooga Metropolitan Airport Authority, said in a release. "As a result, we are seeing more and more passengers flying out of Chattanooga instead of enduring the hassle and inconvenience of driving long distances to use other airports."