On October 28, 2018, about 1210 central daylight time, a Beech V35, N5624S, was substantially damaged when it impacted trees while maneuvering at low altitude near Murfreesboro Municipal Airport (MBT), Murfreesboro, Tennessee. The private pilot was seriously injured. The airplane was privately owned and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight that originated from Gatlinburg-Pigeon Forge Airport (GKT), Sevierville, Tennessee, about 1000.The pilot reported that he attempted to extend the landing gear while in the airport traffic pattern at MBT. He then noticed that the green cockpit indicator was not illuminated and manually extended the landing gear. The pilot subsequently requested that personnel on the ground confirm that the landing gear was extended and he performed a low pass over runway 18. The pilot was told that the landing gear were not extended, so he attempted a go-around, but was "sucked down" into trees by a very strong wind. Other than a possible electrical issue, the pilot reported that there were no other preimpact mechanical malfunctions with the airframe or engine. A witness stated that he and a friend were in the MBT airport terminal building when they heard the pilot announce on the common traffic advisory frequency that his airplane was having "amperage" issues and he might be performing a landing with no radios. The pilot then asked if the witness could visually confirm that the landing gear was extended. The witness agreed and went to a taxiway with a handheld radio while the pilot performed a low pass over runway 18. The witness reported to the pilot that the landing gear was only partially extended. The airplane then proceeded beyond the departure end of the runway, losing altitude, looked like it stalled and descended into trees. Examination of the wreckage by a Federal Aviation Administration inspector revealed damage to both wings and the fuselage. The inspector noted that the alternator switch was in the off position. The recorded weather at MBT, at 1215, included wind from 210° at 14 knots, gusting to 19 knots, and a clear sky.