On January 4, 1996, at 1835 eastern standard time (est), a Piper PA-31-350, N111UC, registered to Executive Aviation Group, was substantially damaged following a loss of control during the landing roll on runway 36 (5,500'x 100'), at the Indianapolis Terry Airport, Indianapolis, Indiana. The airline transport pilot reported no injuries. The 14 CFR Part 91 flight was operating in instrument meteorological conditions. An IFR flight plan had been filed. The flight originated from Cleveland, Ohio, at 1730 est. According to the pilot's written statement, while executing the ILS approach to runway 36, he gained visual contact with the runway two miles out. He also stated that during landing, the left main wheel stuck deep snow and the airplane turned to the left exiting the left side of the runway. Post accident examination of the airplane by the Federal Aviation Administration Principal Maintenance Inspector (PMI), stated that the airplane touched down 42 feet left of centerline and 8 feet right of the runway edge which was covered by approximately 30 inch deep snowdrifts. The PMI stated that the pilot allowed the airplane to drift left about 500 feet down the runway where the left gear encountered the snowdrifts causing the airplane to turn left and become totally engulfed in the deep snow. The airport manager/owner stated that a NOTAM (D) was issued for 2 foot snow banks at the sides with 75 feet width cleared for the runway used. The runway surface was covered with 1 3/4 inches of dry powdery snow.