The National Transportation Safety Board says evidence shows when a Southwest Airlines jet made a hard landing at LaGuardia Airport Monday, its nose gear touched the runway before its main landing gear.
The plane then slid down the runway for nearly 20 seconds before coming to a stop.
It is still not clear why the plane landed the way it did.
Pilots are trained to land on the main landing gear, and then gently ease the nose of the plane down until the nose wheel is on the runway.
The plane was carrying more than 140 passengers and crew, but no one was seriously hurt.