What happened
During an arrival from Atlanta, the flight crew initiated an approach to Chattanooga Airport amidst challenging weather conditions characterized by heavy rainfall and reduced visibility. While on short final for runway 20, the aircraft impacted the approach lighting system approximately 1,600 feet before reaching the runway threshold. Following this impact, the aircraft type (unspecified) struck the ground, resulting in the separation of the left wing. The wreckage slid for an additional 1,200 feet, eventually coming to a stop 250 feet to the left of the runway centerline.
Despite the severity of the impact, all 79 occupants were able to evacuate the aircraft without loss of life. There were seven injuries reported among the passengers, all of which were classified as slight.
Findings
The investigation determined that the pilot failed to identify an excessive rate of descent after passing the decision height. Although the first officer provided two verbal warnings regarding the increasing sink rate, the captain did not take corrective action. It is believed that a visual illusion caused by light refracting through heavy rain on the windshield may have contributed to the pilot's failure to recognize the altitude discrepancy. Furthermore, the descent was exacerbated by wind shear present in the lower levels of the approach path and a glide slope that was trending toward the lower signal limit.