Tuesday, September 15
An investigative hearing into a deadly mid-air collision of a US Army helicopter and a passenger plane that killed 67 people in Washington has revealed a discrepancy in the chopper's altitude displays.The National Transportation Safety Board (NTSB), the US agency tasked with examining major accidents, held hearings from Wednesday to Friday, with rigorous questioning of experts and various other parties including regulators and air traffic controllers.There were no survivors in the January 29 mid-air collision involving the Sikorsky Black Hawk military helicopter and a Bombardier CRJ700 operated by a subsidiary of American Airlines.The passenger plane from Wichita, Kansas was coming in to land at Reagan National Airport -- just a few miles from the White House -- when the Army helicopter on
