The aircraft touched down on Runway 4R at 23:50:20. About two seconds after the wheels touched down, First Officer Origel stated, "We're down. We're sliding!" Because the pilots failed to arm the autospoiler, the spoilers did not deploy automatically on landing, and the flight crew did not deploy them manually. Autospoilers and autobrakes are essential to ensure the plane's ability to stop within the confines of a wet runway, especially one that is being subjected to strong and gusting winds. Spoilers disrupt the airflow over the wings, prevent them from generating lift, and cause more of the plane's weight to be borne by the landing gear. About 65 percent of Flight 1420's weight would have been supported by the plane's landing gear if the spoilers had been deployed, but without the spoilers this number dropped to only 15 percent. With the light loading of the landing gear, the aircraft's brakes were ineffective at slowing down the plane, which continued down the runway at high speed. Directional control was lost when Captain Buschmann applied too much reverse thrust, which reduced the effectiveness of the plane's rudder and vertical stabilizer.