An international team of safety experts believes poor visibility and pilot navigation slipups likely caused last month's crash of a Pakistani airliner that killed 152 people on approach to Islamabad, aviation-industry officials said. The Airbus A321 operated by Airblue Ltd. was en route from Karachi when it flew into heavily forested hills as it was circling to land at the Islamabad airport in fog and rain. Preliminary information retrieved from the plane's flight-data recorder, according to officials familiar with the details, indicates that its engines, flight-control systems and other onboard equipment operated normally before impact. Readouts of the recovered "black box," these officials said, also indicate that the cockpit crew at the last moment may have realized the jetliner was on a collision course with the slope and apparently tried to climb out of danger. The plane impacted near a ridge of the Margalla Hills. Early reports indicated that many flights into Islamabad had been cancelled or diverted that morning due to poor visibility, but some eyewitnesses said the weather improved somewhat before the Airblue plane's approach. It was the second crash of a Pakistani airliner in four years, prompting renewed concerns about the country's aviation safety amid rapid airline industry expansion. Started in 2004 by Pakistani businessman and politician Shahid Khaqan Abbasi, Airblue has quickly grown into the nation's No. 2 carrier behind state-owned Pakistani International Airlines Corp. While the Islamabad probe is far from finished and no determination s have been made, Airbus last week gave the strongest signal yet that it essentially has ruled out aircraft malfunction as a probable cause of the crash In a message to all A321 operators around the world, said a person familiar with the details, Airbus said information uncovered so far about the Islamabad accident provides "no basis for any recommendations" related to airplane systems or performance. Among aviation-safety experts, such a message is tantamount to saying investigators strongly believe mistakes by the cockpit crew, rather than any airplane malfunctions, most likely were responsible for the crash. The message was cleared by Pakistani investigators, further indicating that the team of international experts agrees that the accident didn't stem from any airplane problems. A spokesman for Airbus, a unit of European Aeronautic Defence & Space Co., said the company is working with Airblue and the investigating authorities, but gave no further details. A spokesman for Airblue said the investigation "is still not completed, so we cannot say anything at the moment about the causes." In another sign that investigators are focusing on navigational errors, one safety expert said the U.S. National Transportation Safety Board opted against sending a team to Pakistan once engine issues effectively were ruled out as possible primary or contributing causes. Nevertheless, the board is participating in the investigation from its offices in Washington. A Pakistani International Airlines jet crashed in June 2006 after taking off from the city of Multan, killing all 45 people on board. Following the crash, the European Union partially banned Pakistani International Airlines from EU airspace, but the ban was lifted in 2007 after the carrier made safety improvements.(wsj)