The US government admits the Federal Aviation Administration and the Army played a role in causing the collision between an airliner and a Black Hawk helicopter near Washington, killing 67 people.
The official response to the first lawsuit filed by one of the victims' families said the government is liable in the crash partly because the air traffic controller violated procedures about when to rely on pilots to maintain visual separation that night.
The filing said the Army helicopter pilots' "failure to maintain vigilance so as to see and avoid" the airline jet makes the government liable.
But the filing suggested that others, including the pilots of the jet and the airlines, may also have played a role. The lawsuit also blamed American Airlines and its regional partner, PSA Airlines, for roles in the crash, but those airlines have filed motions to dismiss.
At least 28 bodies were pulled from the icy waters of the Potomac River after the helicopter apparently flew into the path of the American Airlines regional jet while it was landing at Ronald Reagan National Airport in northern Virginia, just across the river from Washington, D.C., officials said. The plane carried 60 passengers and four crew members, and three soldiers were aboard the helicopter.
Robert Clifford, one of the lawyers for the family of victim Casey Crafton, said the government admitted "the Army's responsibility for the needless loss of life" and the FAA's failure to follow air traffic control procedures while "rightfully" acknowledging others - American Airlines and PSA Airlines - also contributed to the deaths.
The families of the victims "remain deeply saddened and anchored in the grief caused by this tragic loss of life," he said.
The government's lawyers said in the filing that "the United States admits that it owed a duty of care to plaintiffs, which it breached, thereby proximately causing the tragic accident."
American Airlines said "plaintiffs' proper legal recourse is not against American. It is against the United States government ... The court should therefore dismiss American from this lawsuit."Â
The National Transportation Safety Board will release its report on the cause of the crash early next year.
Investigators have already highlighted a number of factors that contributed, including the helicopter flying 24m than the 61m limit on a route that allowed only scant separation between planes landing on Reagan's secondary runway and helicopters passing below.
The NTSB said the FAA failed to recognise the dangers around the busy airport even after 85 near misses in the three years before the crash.
Before the collision, the controller twice asked the helicopter pilots whether they had the jet in sight, and the pilots said they did and asked for visual separation approval so they could use their own eyes to maintain distance.
FAA officials acknowledged at the NTSB's investigative hearings that the controllers at Reagan had become overly reliant on the use of visual separation. That's a practice the agency has since ended.