Legislation to require all aircraft flying around busy airports to have key locator systems to prevent midair collisions failed to win approval in the House on Tuesday.

The National Transportation Safety Board says the placement of a helicopter route so close to Reagan National Airport's secondary runway was a key factor in causing a midair aircraft collision that killed 67 people near Washington, D.C., a year ago.

So many things went wrong last Jan. 29 to contribute to the collision between an airliner and a U.S. Army helicopter that killed 67 people that the National Transportation Safety Board isn’t likely to identify a single cause at its hearing Tuesday.