CHARLOTTE, N.C. -- As airlines prepared to report second-quarter earnings amid low expectations, US Airways (LCC) said Tuesday that the decline in travel will force it to eliminate 600 positions this fall.The carrier said it will close the Las Vegas airport club and the Phoenix city ticket office, reduce staff at the Phoenix airport club and in central load planning and transition to outside vendors for ramp service functions at nine airports, the majority of which support Express flying. The stations are in Burbank and Long Beach, Calif; Colorado Springs, Colo.; Boise, Idaho; Wichita, Kan.; Omaha, Neb.; Austin and El Paso, Texas, and Milwaukee. "Today's economy demands we continue to look for ways to control costs," said Robert Isom, chief operating officer, in a letter to employees. He also cited "the fall off of business demand and a significant decline in revenue." Last year, attrition mitigated the need for layoffs, Isom said. But this year, attrition hovers in the low single digits, and "we find ourselves with more employees than our operation requires," he said. AMR ( AMR) will report second-quarter earnings Wednesday. Analysts surveyed by Thomson Reuters estimate the carrier will lose $1.28 a share, compared with a loss of $1.13 a share in the same period a year earlier. Revenue is estimated to total $4.9 billion, down 21%. Southwest ( LUV) will report on Thursday. Analysts estimate the carrier will earn 8 cents, down from 16 cents. Revenue is estimated to be $2.6 billion, down 9%.