SAN DIEGO -- If San Diego can find a way to build a large airport, perhaps at one of its military bases, it could become a bustling, prosperous international hub, federal aviation officials and regional planners say.

In large part because of the soaring economy of Asia -- particularly China -- international air traffic through Southern California is expected to nearly triple between now and 2030, according to the Southern California Association of Governments, a regional planning agency in Los Angeles.

And because Los Angeles International Airport is approaching a growth cap, and few airports are stepping forward to pick up the slack, San Diego is in position to snare a large share of the increase, the nation's aviation chief said in a visit to the area last week.

Marion C. Blakey, administrator of the Federal Aviation Administration, said that opportunity will slip through San Diego County's hands if the county continues to rely on the one runway at Lindbergh Field.

The administrator's comments came as the San Diego County Regional Airport Authority approaches a June decision on whether to build an airport somewhere in San Diego or adjacent counties, or add a second runway at the cramped, 661-acre Lindbergh Field. Lindbergh, while offering convenient access to downtown San Diego and the region's tourist attractions, is the nation's busiest single-runway airport.

The airport authority's preferred long-term airport solution will be presented to county voters in a nonbinding November ballot measure.

It remains to be seen whether San Diego County can take advantage of the opportunity and develop the size and type of airport that can fill Southern California's international need.

After more than three years of studies, the county appears to be left with the choice it had before it asked the Legislature to create an airport authority to study sites for a new airport: The local bases that military officials continue to insist are not, and will not ever, become available; and Lindbergh with its one, relatively short runway.

Candidate sites for a new airport include the southwest corner of Camp Pendleton Marine Corps Base, two miles east of Interstate 5 and 1 1/2 miles north of Highway 76; Miramar Marine Corps Air Station; Naval Air Station North Island, which would be used in a Lindbergh expansion; Campo, in southeastern San Diego County; Borrego Springs, in northeastern San Diego County; a site along Interstate 8 in Imperial County; and March Air Reserve Base in Riverside County.

According to an 84-page study delivered to the authority last week by aviation consultants, Miramar and Lindbergh/North Island would offer the best opportunities for tapping into the international market. Authority board member Bill Lynch of Rancho Santa Fe suggested Miramar would be a perfect fit for the task.

"The bottom line is that we would have a ton of international flights," Lynch said.

Another international airport

At times, critics of efforts to expand the county's air-traffic capacity have suggested San Diego doesn't need a big airport because it will never be a major hub. It is too close to Los Angeles International and located on a "cul-de-sac" of the nation's aviation system, they have charged.

The FAA's Blakely dismissed those arguments, saying Southern California is destined to play a prominent role in an expanding global economy, and the region needs an airport to back up LAX.

"It doesn't necessarily have to be San Diego," said Marney Cox, chief economist for the San Diego Association of Governments, the county's regional planning agency. "But Southern California has to have another international airport."

That airport will need to absorb Southern California air travel demand that is expected to swell by 70 percent over the next quarter-century, from 100 million passengers to 170 million in 2030, said Hasan Ikhrata, planning and policy director for the Southern California Association of Governments.

About 17 percent of today's total is international traffic, and the international share of the region's passenger count is forecast to reach 27 percent by 2030, Ikhrata said. He said that surge will be driven in large part by a more than tripling of Asian traffic, from 5 million passengers to 16.5 million.

Much of the Asian surge will be driven by China.

"Their growth has been unbelievable in the last few years, and we expect it to continue," Ikhrata said. "They have not maximized their potential yet. If you visit China, you will see the huge investments in infrastructure."

Ikhrata noted that the Chinese are constructing speedy "maglev" rail systems that use electric magnets to propel trains as fast as 300 mph on a cushion of air.

"And they are building highways like there is no tomorrow," he said.

World's 10th-largest economy

China's investment in air travel is following a similar track, said Laura Brown, spokeswoman for the FAA in Washington.

"The Boeing Co. is projecting that China will buy more than 2,500 new (jet) airplanes over the next 20 years," Brown said. "China is making tremendous inroads in building its aviation infrastructure."

Brown said the world's most populous country recently completed three new air traffic control centers and has plans for four more. She said the Chinese are building airports of large and medium size.

"Asia, as a whole, is projected to see its air traffic grow 6 percent each year," Brown said. "And, obviously, China is a big part of that."

That growth is expected to ripple across the Pacific Ocean, creating economic opportunity all along the West Coast, she said.

Ikhrata said it would be natural for Southern California to seize much of that opportunity because it has large Asian-American communities and because the huge regional economy is a magnet for international trade. If Southern California were treated as a country, he said, it would rank as having the world's 10th-largest economy.

Erik Bruvold, vice president of public policy for the San Diego Regional Economic Development Corp., said, "the flights to China and to the western part of the Pacific Rim are going to have to go through some West Coast airport, and that could be through a new San Diego International Airport that is equipped to handle that traffic."

But clearly, said Brown, that opportunity is going to be available only for regions that plan far ahead.

The Southern California Association of Governments, which makes long-term plans for most of Southern California -- with the notable exception of San Diego County -- has been trying to do just that. In April 2004, it adopted a regional transportation plan for six counties, including Riverside and Imperial, that makes provisions for handling its proportionate share of the 170 million projected passengers for 2030.

A cornerstone of that plan is a strategy to shift much of airline-passenger growth away from LAX that, up to this point, has been the hub for international traffic and the take-off point for most domestic flights. At 63 million passengers, Los Angeles handles almost two-thirds of the region's air traffic.

In the wake of the Sept. 11, 2001, terror attacks and growing complaints about noise, Los Angeles politicians decided to substantially upgrade security there and establish a ceiling on LAX's future growth. As a result, Ikhrata said, LAX traffic will stop growing once it reaches 78 million passengers.

"They're going to reach the cap by 2015, if not earlier," he said.

'Somebody's fantasy'

And it's not as if the commercial airports in Orange County, Long Beach and Burbank are going to pick up the slack. Ceilings have been established for those airports as well, Ikhrata said.

Operating under those constraints, the Southern California association put together a long-range transportation plan that elevates the future roles of airfields in such remote places as Palmdale, San Bernardino and Riverside. In the case of Riverside, the association is counting on March taking as many as 8 million airline passengers in the year 2030.

Riverside County officials, however, suggest it is unlikely the military reserve airfield will fill such a role, particularly when delivery giant DHL had to withstand stiff neighborhood opposition recently in order to establish a Southern California base of operations there.

"The jury is still out on whether the noise on night flights is going to be too problematic even for that," said Riverside County Supervisor Bob Buster, who also sits on panel that makes policy for March development.

Buster termed the association's allocation of 8 million passengers unrealistic from a political standpoint and impractical because there is not enough room for passenger terminals.

"It's somebody's fantasy, really," he said. "I don't think the communities here would ever support that. The base is too surrounded by housing at this point."

The only airport that seems prepared for the anticipated spike in traffic is Ontario International that handles 7 million passengers, and is projected to reach 30 million in 2030.

"Ontario is going to become like our version of Kennedy," said association spokesman Jeff Lustgarten, referring to New York's second airport.

And, of course, the opportunity to plant a second major airport in Orange County evaporated a few years ago when residents there rejected using the former El Toro Marine Corps Air Station for that purpose.

It all adds up to an opportunity for San Diego to step up and become the region's next international hub, Ikhrata said.

Contact staff writer Dave Downey at (760) 740-5442 or ddowney@nctimes.com.