A U.S. Army Black Hawk helicopter collided with an American Airlines jet near Reagan National Airport, killing all 67 on board. The NTSB is investigating missed air traffic control transmissions, altitude discrepancies in the helicopter’s cockpit, and the possible use of night vision goggles by the pilots. Preliminary findings suggest that critical instructions may not have been received by the crew, which raises significant safety concerns. It may take over a year to finalize the investigation and report.