Accident Overview
On April 8, 2016, about 0930 central daylight time, an MD Helicopters (formerly Hughes) 369A helicopter, registration N298SD, collided with a building and trees during takeoff at the Staggs Heliport (TE93) in Weatherford, Texas. The commercial pilot, who also held an airframe and power plant mechanic certificate, sustained serious injuries. The helicopter was substantially damaged. The flight was conducted as a day, visual flight rules (VFR) maintenance check flight under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from the Staggs Heliport about 0930.
Pilot Statement
The pilot submitted a written statement to the National Transportation Safety Board (NTSB) investigator-in-charge on April 30. He reported that during a battery installation on the helicopter, he locked the left side anti-torque (tail rotor) pedals in the cockpit to keep them out of the way and subsequently forgot to unlock them. While conducting a powered maintenance check after an engine installation on the ground, he was checking the governor with his seat restraint system on in the right seat. He stated that he pulled the collective to check at a hover, and the helicopter departed the ground, spun several times, traveled about 40 feet, and collided with a building and trees. He described the incident as a maintenance error and verified that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
Aircraft and Wreckage Details
The helicopter was originally manufactured as an OH-6A for the US Army and later issued a standard airworthiness certificate by the Federal Aviation Administration (FAA). Examination of the wreckage revealed that the helicopter came to rest with its left side against a small group of trees near a residential building. Both skids had collapsed. Three of the four main rotor blades exhibited several bends along their length due to impacting trees and the building, while one blade separated at the blade root. The fuselage bottom showed crushing consistent with a downward impact with terrain. The tailboom was bent at about the midpoint between the tail rotor and the fuselage, and the left side of the tailboom was crushed just forward of the tail rotor system. The lower vertical fin displayed impact damage on the lower left side.
Inside the cockpit, the anti-torque pedals were observed with the left pedal on the right side positioned in place with an adjustment pin installed; the right pedal on that side was also in place but missing the adjustment pin. On the left side, the left anti-torque pedal was displaced from the pedal arm and lying against the center console with the adjustment pin missing, while the right pedal was positioned in place with an adjustment pin. The center section of the right cockpit windshield was punctured during the accident sequence.
Additional Information
The FAA aviation safety inspector reported that various mechanic tools were found underneath the floor board on the right side of the cockpit, but this foreign object debris did not contribute to the accident. The public docket includes excerpts from the US Army Operators Manual for the OH-6A regarding the preflight checklist and anti-torque control system, as well as MD Helicopters Service Letter SL369H-124R3 (2004), which describes maintenance and operation requirements for surplus 369A (OH-6A) series helicopters and notes that failure to comply with regulations may lead to loss of control.