To update the February 12 forced landing of its TH180 prototype, Enstrom released a statement today praising the ruggedness of the light single, and citing a possible cause for the accident. In part, the statement read, “Preliminary investigation indicates that a piece of flight test instrumentation in the main drive system failed, disconnecting the engine from the drive train.”
While on a test flight from Menominee-Marinette Twin County Airport in Michigan, where the Enstrom factory is located, the prototype autorotated to a hard landing on a residential street after a loss of rotor speed. The engine continued to run, but the main rotor hit a utility pole and the helicopter slid about 300 feet. It was substantially damaged, including collapsed skids, and damage to the tail cone, pylon center section and the lower section of the cockpit structure. There was no fire or fuel spill and the pilot, the only one on board, was uninjured.
William Taylor, co-program manager of the TH180 program said production of the second TH180 test airframe is ahead of schedule and he anticipates it will fly in April or May. According to Enstrom’s website, the TH180 was expected to be certified this year. Taylor said, “We expect this accident will cause only a minimal delay for the program.”