Shortly after 10 a.m. , Ferguson began his descent to Pittsburgh , believing it to be much closer than it actually was .
Heavy cloud cover prevented Ferguson from seeing any landmarks , and he was relying wholly upon instruments .
Shortly after 10 a.m. , Ferguson began Ferguson 's descent to Pittsburgh , believing it to be much closer than it actually was .
Heavy cloud cover prevented Ferguson from seeing any landmarks , and he was relying wholly upon instruments .