WASHINGTON — A key House subcommittee has launched an investigation into the fatal air collision near Washington in January between an Army Black Hawk helicopter and an American Airlines flight that killed 67 people, the deadliest U.S. air disaster in nearly 25 years. 

The probe is being launched by South Carolina Rep. William Timmons and Virginia Rep. Suhas Subramanyam, the top Republican and Democrat, respectively, on the House Oversight Subcommittee on Military and Foreign Affairs. They announced the inquiry Thursday with a letter to Defense Secretary Pete Hegseth requesting a briefing by April 1 for the subcommittee’s members on the circumstances of the midair collision and “what measures the U.S. military are taking to ensure calamities of this nature do not occur in the future.”

“Washington, D.C.’s airspace is among the most complex and heavily regulated in the nation," the lawmakers wrote to Hegseth. "DCA operates within the tightly controlled Flight Restricted Zone (FRZ), making it one of the busiest and most sensitive airspaces in the country. DoD plays a critical role in managing and securing this airspace, with military aircraft frequently conducting operations in and around the National Capital Region.”

According to the lawmakers, Federal Aviation Administration data has on record 30 “near-midair collisions” around Ronald Reagan Washington National Airport, where the American Airlines flight out of Wichita, Kansas, was slated to land in January. Among those 30 incidents, one-third involved “military aircraft and seven including helicopters,” according to the letter. 

“Initial reports of the crash indicated a potential miscommunication between DCA air traffic control and pilots of the UH-60 when they were instructed to avoid the incoming Canadair Regional Jet 700,” the lawmakers continued. “Additionally, the crew of the UH-60 reportedly were wearing night vision goggles which may have impaired the pilots’ peripheral vision.”

In the days after the crash, senior Defense Department officials and the Army both launched investigations into the collision. All three Army personnel aboard the Black Hawk were killed in the collision, along with all 64 passengers and crew on the American Airlines flight. 

"As with all Congressional correspondence, the Department will respond directly to the Members," a Pentagon spokesperson said in an email on Thursday.

On Tuesday, the chair of the independent federal aviation watchdog said that the pattern of helicopter traffic and commercial airline flight paths near Reagan National “pose an intolerable risk to aviation safety” and that the board members “remain concerned about the significant potential for a future midair collision at DCA” and recommend “a permanent solution today.”

Transportation Secretary Sean Duffy responded the same day by accepting the National Transportation Safety Board’s recommendations, including “permanently restricting non-essential helicopter operations” around the airport and “eliminating mixed helicopter and fixed wing traffic.” Duffy also pledged to use artificial intelligence and other tools to examine other U.S. airports with similar mixed craft air traffic to attempt to remedy any similar unsafe practices elsewhere in the country.

Timmons, the South Carolina Republican and subcommittee chair, is a captain and JAG officer in the South Carolina Air National Guard. Subramanyam, the Virginia Democrat, is serving in his first term in Congress after four years in the Virginia House of Delegates and a stint advising the Obama White House. Several of the passengers on the airliner who died were residents of his district.