section_path: Investigation
section_name: Investigation
paragraph_text: Investigation
  
  The National Transportation Safety Board (NTSB), the FAA, the US Department of Defense, and the US Army announced they would launch investigations into the collision. The NTSB prepared an investigation team to send to the accident site. To retain needed personnel after the crash, the agency acquired an exemption from the "Fork in the Road" memo which purported to allow all of its agents to quit with severance paid through September 2025. The Federal Bureau of Investigation (FBI) also stated it would help with the response. However, there were no indications of terrorism or criminal activity. The Transportation Safety Board of Canada (TSB) deployed two investigators to help the investigation, since the Bombardier CRJ700 was designed and manufactured in Canada. On the evening of January 30, the flight recorder ("black box") of Flight 5342 was recovered from the wreckage and brought to the NTSB lab for evaluation. The helicopter's flight recorder was recovered on January 31.
  
  According to the NTSB, at the moment of impact, the helicopter was at a radio altitude of 278 feet (85 m). Reagan National requires helicopters on that route to stay at or below 200 feet (61 m) above mean sea level. The NTSB is investigating what altitude the barometric altimeter displayed to the helicopter crew, which was not recorded by the flight recorder. Investigators would normally calculate the barometric altitude displayed to the crew using pressure altitude recorded by the flight recorder, but investigators determined that the data was not valid.
  
  Senators Ted Cruz and Tammy Duckworth addressed questions about the automatic dependent surveillance-broadcast system (ADS-B) which was reportedly turned off on the Black Hawk. Some flight data was being sent from the aircraft but the safety system sends what is considered the most-accurate data. The NTSB confirmed ADS-B was not broadcasting from the helicopter and said they would investigate if there was an equipment malfunction or it was turned off.
  
  A single air traffic controller was managing both aircraft at the time of the crash, an arrangement deemed "not normal" for that time of day at the airport. According to the helicopter's cockpit voice and data recorder, the helicopter crew may have missed parts of two transmissions made by the air traffic controller regarding the jet. Two minutes before the collision, the part of the transmission which said that the plane was "circling" to runway 33 was not heard on the recording. Seventeen seconds before the crash, the part of the transmission stating "pass behind the" was interrupted by the helicopter crew keying their mic to communicate with the air traffic controller.
  
  About nineteen seconds before impact, the crew of Flight 5342 received an automated traffic advisory alert from the TCAS system. Data from the flight recorder showed the PSA jet pitched up about one second before impact, but investigators did not say whether this was an attempted evasive maneuver by the PSA pilots.