The NTSB's investigation into the January 29 collision between an American Airlines jet and a U.S. Army Black Hawk near Washington D.C. highlights serious communication failures. They revealed the helicopter crew may not have received crucial air traffic control instructions to pass behind the jet. Investigators also found discrepancies in altitude readings, with the Black Hawk recorded at 278 feet during impact, above its 200-foot limit. All 67 victims, including crew members and passengers from both aircraft, were killed. The NTSB continues to analyze data and will conduct a visibility study given the crew's likely use of night vision goggles.