KARACHI: The Pakistan International Airlines (PIA) said on Saturday it remained unaffected by a recall of Airbus A320 jets by the European planemaker, with global airlines scrambling to fix a software glitch that temporarily grounded aircraft in Asia and Europe and threatened travel in the United States. Airlines around the world reported short-term disruptions heading into the weekend as they fixed software on the widely used commercial aircraft after an analysis found the computer code may have contributed to a sudden drop in the altitude of a JetBlue plane last month.