On May 10, 2016, at 1730 central daylight time, a Beech B100, N86TR, impacted runway 18 when the right main landing gear collapsed during landing at Dexter Municipal Airport (DXE), Dexter, Missouri. The airplane sustained substantial damage. The pilot, flight instructor, and two passengers were uninjured. The airplane was operated by Dexter Air LLC under 14 Code of Federal Regulations Part 91 as an instructional flight that was not operating on a flight plan. Visual meteorological conditions prevailed for the flight that last departed from Jonesboro Municipal Airport, Jonesboro, Arkansas at 1650 and was destined to DXE. The pilot stated that the purpose of the flight was a Beechcraft B100 initial training flight with a second pilot who occupied the right pilot seat. According to the Federal Aviation Administration inspector, the flight instructor was in a non-seated position between both pilots. The left seat pilot stated that they flew about 3 hours and had taken turns performing turns, stalls, slow flight and approaches. He stated that the accident landing was the third landing of the day that he performed. He said that during the left downwind approach for landing on runway 18, he performed the airplane checklist items that the flight instructor read to him. The left seat pilot said that the landing gear extended, and the three landing gear position indicator lights illuminated green. The left seat pilot said that during touchdown, the right side of the airplane descended lower than the left side and then the right main landing gear collapsed. The airplane veered off and into a grass area adjacent to the runway. The aircraft came to rest approximately 2,518 feet from runway 18 touchdown end and 100 feet west of the runway edge in a field of grass. The right hand main gear was collapsed, right hand prop blades were bent and the right wing leading edge and tip was damaged. Evidence of fuel leakage was noted surrounding the right wing in the grass. The wing top skin outboard of the engine nacelle displayed evidence of wrinkling. Post-accident examination revealed the bottom right wing skin to the integral fuel tank was torn resulting in an approximate five by three inch hole. The right main gear actuator assembly exhibited numerous bent parts and was broken out of its mounting structure. The inboard top actuator mounting structure was torn away from the airframe. The right nacelle fuel tank bulkhead was ruptured with the top of the gear actuator resting inside the tank area. The top wing skin wrinkling was not as evident post recovery but still shows signs of damage. Puncture damage to the fuselage pressure vessel was noted in 5 places below the copilot side window and a two-inch crack or tear was found on the belly skin approximately centered between the main gear legs. The rigging for the landing gear system could not be checked nor could functional gear swing test be performed due to damage incurred to the system from the accident.