Approach and Landing
The crew reported breaking out of clouds at about 744 feet above ground level (AGL) during an Instrument Landing System (ILS) approach, with the ceiling described as ragged. At approximately 500 feet AGL, the captain activated the windshield wipers. The first officer, who was flying the aircraft from the right seat, executed a smooth touchdown.
Rain and Visibility
Shortly after touchdown, the rain became extremely heavy, causing the runway lights to appear diffused but remain somewhat visible.
Drift and Runway Excursion
The captain informed the first officer that the aircraft was drifting left, but the first officer did not detect the drift. The captain took control but was unable to prevent the aircraft from drifting off the runway. During the excursion, three runway lights were knocked out, and the aircraft received minor damage before being steered back onto the runway.
Hydroplaning Evidence
Marks on the runway indicated that the tires had hydroplaned.