The merger of major airlines generally results in fewer competitors, higher airfares.

Fare cities

The U.S. Department of Transportation reports on the average round-trip fares at the nation's top 100 airports. Some of the latest findings:

Rank/City 2Q 2012 2Q 2013 Change

1. Huntsville, Ala. $513 $547 +6.6%

30. Greenville/Spartanburg $408 $407 -0.2%

34. Charlotte $415 $406 -2.4%

42. Charleston $465 $395 -15.1%

52. Atlanta $373 $383 +2.7%

58. Jacksonville, Fla. $387 $376 -2.8%

100. Atlantic City, N.J. $169 $159 -5.9%

Note: Columbia and Myrtle Beach aren't in the top 100.

So what does the marriage last week of American Airlines and US Airways mean for Charleston International, South Carolina's busiest airport?

The short answer is, it depends.

Aviation consultant Greg Raiff, CEO of New Hampshire-based Private Jet Services, said the move doesn't bode well for secondary markets that aren't hubs, including Charleston.

"Recent history makes it quite clear that we can all expect to see substantially higher rates and reduced services as a result of this merger," said Raiff, referring to combinations of other big carriers in recent years.

Among them, United and Continental in 2010, Delta and Northwest in 2008, and US Air and American West in 2005.

Charleston could lose some service, Raiff said, citing an agreement by American and US Airways to give up 52 landing slots at Reagan Washington National Airport and 17 at LaGuardia Airport in New York.

US Airways has been offering five flights per day to Washington National, the only airline in Charleston to offer direct flight service to that airport. Neither US Airways nor American flies to LaGuardia from Charleston, so those slots are not directly affected.

Corey Winer, station manager at US Airways at Charleston International, said no decision has been made about changes to any local flights to Washington National.

Whatever slots are given up, Raiff doesn't see much of an impact on major hubs such as Atlanta.

"Secondary markets like Charleston have the most to lose by this merger," he said.

Raiff said other airlines such as Southwest and JetBlue, which are picking up new slots in Washington, are going to use them in markets where they can make the most money.

"For JetBlue and Southwest, that might not be Charleston," he said. "JetBlue could choose another New York-to-Washington flight rather than a Charleston-to-Washington one. If Charleston loses one, let alone two, of the connecting flights, the result will be very higher prices for the few remaining seats. Because of the multiplier effect, for businesses it becomes a lot more expensive to travel outside of town and to recruit new business."

Ripple effect

The trickle-down also could affect the travel industry, no small part of Charleston's nearly $4 billion tourist trade that saw 4.83 million visitors in 2012, many of them through the airport.

American and US Airways together make up 30 percent of the air traffic at Charleston International, according to Charleston County Aviation Authority spokeswoman Becky Beaman. That's only second to Delta and its 35.1 percent share. Southwest, which started service in 2011, now carries 20 percent of the passenger load. United, which merged with Continental, and JetBlue account for the rest.

Paul Campbell, director of airports at the Aviation Authority, doesn't believe Charleston International will lose any service. He points to the local growth in passengers, saying planes "coming in here are pretty much loaded."

"I see it as an opportunity for Charleston," he said. "Several routes will be given up by the two airlines. I see an opportunity for other airlines to pick up those cities. If they dropped one of the routes, we would expect one of the other airlines to pick it up."

Charleston International saw about 2.6 million boarding and arriving passengers for the 12-month period that ended in June. That's up by about 1 million over the past decade. The number is expected to grow to about 3.48 million, or about 30 percent, over the next 10 years, according to Aviation Authority projections.

Southwest is now the third-largest carrier at Charleston, and it wooed away at least some of its passenger base from other carriers such as United, Delta and US Airways.

But overall, many of the other current carriers at Charleston picked up passengers at the same time Southwest was growing, showing a trend of consumer demand in the local area's strengthening economy, especially with the growth of Boeing Co. and the attention the Holy City has garnered as a tourist destination.

Gary Edwards, an airline consultant for the Aviation Authority and the Charleston Area Convention and Visitors Bureau, realizes the downside could come from higher fares if a flight is lost because of the merger. But, like Campbell, he believes the Charleston market is so strong another carrier will step in.

"We are performing so well on so many levels with tourism and our aerospace cluster growth, we have the attention of the airlines," Edwards said. "I do not see a downturn in the number of passengers. If something meaningful is taken away from us, I feel comfortable one of the other airlines will replace it. We are in a really good place right now."

Flying lower

Charleston International's fares have been trending downward in recent years after Southwest Airlines and JetBlue Airways flew into town.

Based on the latest available figures from the second quarter of 2013 from the U.S. Department of Transportation, the average airfare in Charleston was $395, a $70 savings, or 15.1 percent decline, over the April-June period in 2012.

The national average for this year's second quarter was $378, down 3.6 percent. Charleston's rates rank 42nd highest among the nation's top 100 airports. For comparison, Charleston's rates have dropped nearly 36 percent since 2000, when the average fare was $615.

Reach Warren L. Wise at 937-5524 or