Preliminary flight data from ill-fated American Airlines Flight 587 showed the aircraft was buffeted twice by turbulence from another big aircraft seconds before it began its final fatal descent.
Safety investigators said today the final turn to the left occurred even as crew controls were set to the right.
This suggests the Airbus A300 was no longer responding to pilot commands several seconds after the second bout of turbulence and just before crashing on Monday.
The crash killed all 260 aboard and at least five on the ground.
National Transportation Safety Board (NTSB) officials said there was movement noted on the flight data recorder that was consistent with two similar turbulence encounters caused by the wake of another aircraft.
But it remained unclear if the force of the wake turbulence - suspected to be from a Japan Air Lines Boeing 747 that took off just before the American Airlines plane - was enough to throw the doomed jetliner more than four miles behind it out of control.
"We are also looking at other events that went on," NTSB deputy director of aviation safety Mr Thomas Haueter said. These include various stresses that could have been placed on the tail.
Investigators also noted three separate rudder movements that correspond to three increasingly violent lateral movements seconds after the turbulence and before the aircraft fell into a final dive.