An erupting volcano in Alaska’s Aleutian Islands sent up a cloud of ash Friday, prompting the National Weather Service to issue an inflight warning to pilots. The Alaska Volcano Observatory says the Shishaldin Volcano began erupting July 11. A U.S. Coast Guard overflight confirmed lava erupted the same day within the summit crater. A significant explosion at 1:09 a.m. Friday produced an ash cloud that reached up to 40,000 feet and drifted south over the Pacific Ocean. Volcanic ash can cause a jet engine to shut down. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc.