A federal jury cleared jet manufacturer McDonnell Douglas Corp. and held Northwest Airlines solely responsible for the second-worst air disaster in U.S. history, a 1987 crash that killed 156 people.

The jury deliberated 16 days before finding that Northwest was negligent in training and supervising its crew and that the negligence of the airline and crew contributed to the accident.Northwest had argued it received flawed equipment from McDonnell Douglas, maker of the MD-80 that went down on takeoff from Detroit Metropolitan Airport.

The trial that ended Wednesday was to determine which company - the airline and the jet manufacturer - paid what portion of out-of-court settlements reached previously with most of the victims' families.

The verdict means Northwest must pay 100 percent. The settlements have been sealed and the amounts given to the victims have not been disclosed.

"Obviously we are very pleased," said McDonnell Douglas attorney Donald Shely said. "The evidence fully justifies it."