On May 31, 1999, at 1458 central daylight time, a Cessna 195 single-engine tail wheel equipped airplane, N2151C, owned and operated by the pilot, was substantially damaged during landing at the Montgomery County Airport near Conroe, Texas. The private pilot and the three passengers were not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The flight originated from the David Wayne Hooks Memorial Airport, Houston, Texas, at 1430. The pilot reported that during landing on runway 19, he made a wheel landing, and a tail high attitude was maintained until the tail started to lower with "speed drop off." During the landing roll, the pilot "heard a loud pop, then about 2 seconds later the [left] wing dropped to the runway and we started to slide." The aircraft slid about 50 to 75 feet before coming to a stop. The pilot found the left main landing gear in the middle of the runway, approximately 80 to 90 feet from where the airplane came to a stop. An examination of the aircraft by the FAA inspector revealed that the left main landing gear was separated from the fuselage, the left wing was wrinkled, and the left aileron was damaged. The inboard section of the separated left main landing gear spring was sent to the NTSB Materials Laboratory for examination. The examination revealed that "fatigue initiated from an area that contained fretting damage from contact with the clamping mechanism. Fretting on the upper surface extended almost to the aft edge of the spring. Similar areas of fretting were noted on the bottom surface near the fracture and around the bolt hole." See the enclosed Metallurgist's Factual Report for details of the examination.