20111011023189A

On October 11, 2011, at approximately 23:00 hours, a LR-60, N64MG, was attempting to taxi from the ramp of Lafayette aviation to runway 10 at the Purdue University Airport (klaf), located in west Lafayette, Indiana. Visual meteorological conditions, at night, prevailed at the time of the accident. The aircraft went off the concrete ramp onto a grassy area that separates the ramp and the taxiway. The pilot did not notice this until the nose gear was in the grass. Personnel from Lafayette aviation were available to assist the crew in repositioning the aircraft had the crew stopped the aircraft and asked for help. The crew believed the grass was firm and level, so power was applied in an attempt to cross the grass and gain access to taxiway "c". In this area is a drainage ditch that is approximately six to eight feet deep. The distance from the ramps edge to taxiway "c" is approximately 128 feet. The wheel tracks observed in the grass, showed the aircraft went approximately 141 feet from pavement to pavement. As the aircraft entered the ditch, damage was done to the rear delta fins, which affects the flight characteristics as definded in NTSB 830.2.the aircrat was taxied via taxiway "c", "b" and "e" to the Lafayette aviation ramp where the crew observed the damage and subsequently grounded the aircraft. The FAA was notified the following morning by the pilot in command.a meeting took place at the Purdue University Airport on October 13, 2011. Both pilots were counseled on ramp operations, and aeronautical decision making.