CHICAGO — Soaring fuel costs. Flights cut. Jobs lost. The parent company of United Airlines reported a worse-than-expected quarterly loss Tuesday, citing a string of problems that are hurting other carriers as well. And for travelers, a vacation season of jammed planes, delayed flights and higher fares looms in what’s shaping up as the worst of times for both airlines and their customers. ‘It’s going to be a rough summer,’ said Terry Trippler, a Minneapolis-based travel expert. ‘It’s going to be one where you’ve got to plan another day into your travel schedule’ just to prepare for schedule chaos. Months of rising concerns about the consequences of higher fuel prices jumped to new levels of anxiety among investors on a gloomy combination of developments that sent UAL Corp. shares down a staggering 35 percent and battered other airline stocks. Not only did United post a $537 million first-quarter loss and announce cutbacks accordingly, crude oil surged near the once-unthinkable $120-a-barrel mark and Delta Air Lines Inc. CEO Richard Anderson said domestic carriers would need to raise fares by 15 percent to 20 percent just to break even. With weaker demand because of the economy, cutbacks […]