Investigators are going to have to look at every possible reason a military Black Hawk Helicopter could crash into an American Airlines passenger jet landing at Reagan Airport in D.C. The calls from air traffic controllers for the helicopter to “return to base” raise serious concerns over what may have caused this crash. We even pulled the altitude and flight tracking data that revealed sharp zig-zags and a sudden drop in altitude moments before the crash. Here are the possible reasons behind the disaster: Mechanical Failure Air Traffic Control Failure Human Error Nefarious Action Pilot Suicide Computer Hack ....