section_path: Investigation/NTSB preliminary report and recommendations
section_name: NTSB preliminary report and recommendations
paragraph_text: NTSB preliminary report and recommendations
  
  The NTSB released a preliminary report on March 11, 2025, accompanied by two urgent safety recommendations to the FAA regarding flight traffic decongestion. Investigators reviewed years of encounters between helicopters and commercial aircraft near Reagan National Airport, finding that "at least one traffic collision avoidance system (TCAS) resolution advisory was triggered per month" since 2011.: 18
  
  Helicopters flying within the route 4 corridor, which is designated for operations "at or below 200 feet (61 m)," would have only 75 feet (23 m) of vertical separation from a plane landing on runway 33 if flying directly over the eastern shoreline of the Potomac River. Since route 4 lacks lateral boundaries or instructions to operate a defined distance from the shoreline, this already minimal separation decreases further when a helicopter operates farther from the shore. This vertical separation also decreases if an airplane is operating below the 3° visual glidepath provided by runway 33's precision approach path indicator (PAPI). The board concluded that the proximity of route 4 to runway 33's approach path posed "an intolerable risk to aviation safety."
  
  The NTSB urgently recommended that the FAA close route 4 near the airport during runway 33 landings or opposite-direction takeoffs and designate an alternate helicopter route during those times. NTSB Chair Jennifer Homendy expressed anger that the FAA had not used the same near-miss data her investigators relied on to identify the risk and examine the helicopter routes before the crash occurred and said, "It does make me angry, but it also makes me feel incredibly devastated for families that are grieving."
  
  As of April 1, 2025, the Ronald Reagan Washington National Airport is still facing scrutiny over what led to the mid-air collision.