Air Travel Up in State, Bucking National Trend : Airlines: The recession and fears of terrorist attacks fail to discourage California fliers. But the $20 fares that are filling seats may not last.

Although down elsewhere, air travel is up in California, thanks to $20 one-way fares between the Los Angeles basin and the Bay Area. One airline said its aircraft, normally half empty on weekends, are full. A reservation agent for another said the low-fare flights have been sold out for weeks.

The situation in California is dramatically different from the rest of the nation, where the recession and fears of terrorist attack over the Persian Gulf War have dampened travel, forcing airlines to cut flights. Trans World Airlines recently reduced its European trips by one-third. Other carriers have cut flights to Europe or converted nonstops to one-stop trips.

“The California market is unique,” said Joe Brancatelli, editor of Frequent Flyer magazine.

Apparently for many Californians, $20 one-way fares are too good to pass up. A USAir reservation agent said $20 fares on weekends have been sold out for weeks. On weekdays, cheap seats are available mostly on early morning or early evening flights.

Delta Airlines said its traffic is up 10% to 15% weekdays within the state because of the fares. The airline is doing even better on weekends, with traffic up 30% to 40%. “I don’t think our flights would be half full” without the bargain fares, said Vince Durocher, Delta’s West Coast marketing manager.

The number of seats available at the low fare is limited--and a well-kept secret on the part of the airlines. “It could be that United”--the largest airline in California’s north-south corridor--”has just one $20 seat on some flights,” Brancatelli said.

Evidently, low fares are plentiful enough to help fill planes--especially on weekends, when flights dominated on weekdays by business travelers are nearly empty. Nonetheless, the $20 fare promotion probably won’t be repeated after it expires Feb. 28.

Low fares win few loyal customers for the airlines, because people who fly cheaply normally don’t fly at all. “When the fare cuts go away, the traffic just evaporates,” said analyst Dan Hersh with the Los Angeles brokerage Bateman Eichler, Hill Richards.

Neither have the low fares helped airlines win over business travelers--highly valued airline customers who fly often and usually pay full fare. The tickets require a 21-day advance purchase, making them impractical for business travelers who don’t have time to plan their trips.

Moreover, airlines maintain, the $20 tickets are unprofitable. One estimate puts each airline’s loss from the low fares at $200,000.

The red ink helped force American Airlines and USAir to all but withdraw from California’s north-south corridor. And the airline that first offered the $20 fares--Southwest Airlines--reported a $4.6-million fourth-quarter loss Monday, giving it little incentive to trigger a second fare war. The Dallas-based airline blamed high fuel prices for the loss and said it nonetheless earned $47.1 million for 1990, down from a record $71.6 million in 1989.

In an earlier interview, Southwest Marketing Manager Richard Sweet said it was unlikely that the airline would offer $20 fares again because they are too low. The lowest fare in the market before the promotion, which started Jan. 3, was $59 round trip. It was also introduced by Southwest.

Southwest and other airlines--including Alaska Airlines, America West Airlines and Delta--are studying the California market in the wake of USAir’s decision to drop much of its intrastate service. It isn’t clear whether any of the airlines will pick up any of USAir’s routes.