D.C. Plane Crash: What We Know About the American Airlines Jet and Helicopter Collision

The accident raised concerns about aviation safety.

Investigators from the National Transportation Safety Board, an independent federal agency, are leading the inquiry into the collision. Officials said they would look at the flight data from the two aircraft, review traffic control communications and conduct interviews.

Teams have recovered two so-called black boxes from the plane — a cockpit voice recorder and a flight data recorder — which may offer insights into the moments before the crash. A black box from the Army helicopter was also retrieved, federal officials said on Friday.

Already, questions have emerged about the planes’ flight paths and whether staffing at the air traffic control tower contributed to the collision.

A preliminary report by the Federal Aviation Administration, which was reviewed by The New York Times, found that a controller working that night was performing jobs typically assigned to two controllers: handling helicopters in the airport’s vicinity and also instructing planes that were landing and departing from runways. The staffing at the tower was “not normal for the time of day and volume of traffic,” the report said.

The Army helicopter — which was operating out of Fort Belvoir, Va., with what officials described as an experienced crew, had been approved to fly a specific route that would have let it avoid the American Airlines plane. But it did not follow the intended route, according to four people who were briefed on the matter but not authorized to speak publicly. The route it took was a half-mile away and higher in attitude, they said.

Shortly before the collision, the plane’s pilots were asked to pivot their landing route from one runway to another, according to a person briefed on the event and conversations between an air traffic controller and the pilots overheard on audio recordings.

On Friday, the F.A.A. indefinitely restricted two commonly used helicopter routes into Reagan Airport to all but the most essential flights, calling it a critical new safety measure.

Figure skaters and hunters were among the plane’s passengers.

Figure skaters, their family members and their coaches were among those onboard the plane, according to U.S. Figure Skating, the American governing body for the sport.

Russians, including figure skaters, were also onboard. Among them were the married skating champions Yevgeniya Shishkova, 52, and Vadim Naumov, 55, according to the Skating Club of Boston. They worked as coaches in the United States.

Two skaters from New England — Spencer Lane, 16, of Barrington, R.I., and Jinna Han, 13, of Mansfield, Mass. — were also killed along with their mothers, Christine Lane and Jin Han.

A group of friends who had spent days in Kansas on a hunting trip were on the plane, along with a four-person crew. Officials have not released a list of the victims, but more of their identities have become public.

Army officials on Friday identified two of the three aviators on the helicopter: Staff Sergeant Ryan Austin O’Hara, 28, of Lilburn, Ga., and Chief Warrant Officer 2 Andrew Loyd Eaves, 39, of Great Mills, Md. On Saturday, officials identified Capt. Rebecca M. Lobach, 28, of Durham, N.C., as also having been on board. The Army did not immediately release Captain Lobach’s identity at the family’s request.

Reporting was contributed by Mark Walker, Jack Healy, Julie Bosman, Jenna Russell, Jesus Jiménez, Mitch Smith and Christina Morales.