SAN DIEGO (CNS) - Aircraft equipment malfunctions had public-safety crews hustling to the flight line Tuesday at Lindbergh Field, where two planes made safe precautionary landings over a several-hour period despite the glitches.
   
The first emergency began about 10:45 a.m., when the crew of a Horizon Air dual-propeller commuter plane reported a "system issue'' after taking off from the bayside airport en route to Santa Rosa, Lindbergh Field spokeswoman Rebecca Bloomfield said.
   
The aircraft doubled back and landed without incident about 11:30 a.m., according to Bloomfield. The precise nature of the equipment problem was unclear, she said.
   
In the early afternoon, a Southwest Airlines jetliner heading to San Diego from Las Vegas with 127 passengers aboard reported a problem with a hydraulic system. That aircraft touched down safely at Lindbergh Field about 1:15 p.m., the city Fire-Rescue Department reported.