The Blancolirio Channel on YouTube does a good job of answering questions very early on after aviation incidents like these. He did help me to understand a lot about the potential hazards during that helicopter flight including the use of the night flying goggles by the crew. From what I'm gathering the route and altitude taken by the helicopter flight crew was not as published on the aeronautical charts which put his aircraft in the direct path of the approaching regional jet. Had he hugged the east bank of the Potomac River at the published altitude of 200ft, he would easily have flown below the RJ on his final approach. Whatever his reason for climbing and flying more toward the centerline of the river may never be known. But it was a decision that cost him and 66 other people their lives. Had those restrictions been maintained, we would never have heard this news and all would [still] be right in the aviation world.