The study says San Jose would be hit the hardest, with a more than 9 percent loss, according to consultants at SH&E, an aviation firm the Metropolitan Transportation Commission hired to study the impact of the bullet trains on Bay Area airports.
The $42.6 billion bullet train is expected to begin operation by 2020 and link San Francisco to cities in Southern California.
High-speed rail planners estimate a ride from the Bay Area to Los Angeles would cost about $105, or 83 percent of the average airfare estimated at $125. The trip would take about two and a half hours.
A travel industry analyst said the trains would offer travel less susceptible to delays, more efficient and city center to city center connections.