ERA15LA374

The commercial pilot performed a right pedal turn to land the helicopter on a truck-mounted platform, and, just before touchdown, a pin that connected a push-pull tube to the left anti-torque pedal broke resulting in a loss of directional control. The pilot maneuvered the helicopter away from the truck to avoid striking his employees and tried unsuccessfully to land back on the truck's platform. He then repositioned away from the truck, closed the throttle, and lowered the collective to land, and the main rotor blades struck the side of the truck. Although this make and model of helicopter is typically flown from the right seat, the accident helicopter was equipped with a left-hand "command" kit, and the pilot was flying it from the left seat. In addition, the helicopter was equipped with a tail rotor pedal lockout kit, which was designed to disconnect and lockout the tail rotor pedals to prevent interference by a passenger seated in the copilot's seat, which was, in this helicopter, the right seat. Photographs of the tail rotor pedal assembly revealed that the left expandable pin, which was a part of the tail rotor pedal lockout kit, had fractured, which disconnected the left anti-torque pedal from the tail rotor control system. Fracture analysis could not be performed on the broken pin because the pin was lost in shipping. Therefore, the failure mode for the pin could not be determined; however, it is built to the same strength as the bolts that it is intended to replace.

On September 20, 2015, about 1900 eastern daylight time, a Bell 206L-1, N165BH, was destroyed during a collision with a ground vehicle and terrain following a flight control malfunction and subsequent loss of control near Thomaston, Georgia. The commercial pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local aerial application flight, which was conducted under the provisions of 14 Code of Federal Regulations Part 137.In a telephone interview, the pilot said that the accident occurred at a job site. The purpose of the flight was to establish spray patterns and flow rates and to have the GPS and spray equipment calibrated for the contracted job. He said that he departed from the platform-equipped "mix" truck about 10 minutes before the accident and returned to land on the truck to clean the windscreen of the helicopter. The pilot said that he performed a right pedal turn to land on the truck, and, just before touchdown, a pin that connected a push-pull tube to the left anti-torque pedal broke resulting in a loss of directional control. The pilot maneuvered the helicopter away from the truck to avoid striking his employees and then tried unsuccessfully to land back on the truck's platform. He repositioned away from the truck, closed the throttle, and lowered the collective to land, and the main rotor blades struck the side of the truck. The pilot held a commercial pilot certificate with ratings for airplane multi-engine land and rotorcraft/helicopter. His most recent second-class Federal Aviation Administration medical certificate was issued on July 2, 2015. The pilot reported 11,409 total hours of flight experience of which 40 hours were in the accident helicopter make and model. The helicopter was manufactured in 1979, and at the time of the accident it had been operated for about 16 hours since its most recent annual inspection was completed on September 7, 2015, at 7,977.2 total aircraft hours. The helicopter was equipped with a left-hand "command" kit, and the pilot was flying it from the left seat at the time of the accident. In addition, the helicopter was equipped with a tail rotor pedal lockout kit, which was designed to disconnect and lockout the tail rotor pedals at the copilot's seat to prevent passenger interference. For this make and model helicopter, the left seat would typically be the copilot's seat; however, as the accident helicopter was equipped with a left-hand command kit, the right seat was the copilot's seat. The kit, which was manufactured by Aeronautical Accessories and installed in accordance with supplemental type certificate SR00513AT, could be in either "Lockout" mode to prevent use of the pedals or "Engaged" mode for pedal control. Examination of photographs provided by the operator revealed that the main transmission and the engine were torn from their mounts, and the aft fuselage was destroyed. The tail boom was separated just aft of its mount. Photographs ofthe tail rotor pedal assembly revealed that the left expandable pin, which was a part included in the tail rotor pedal lockout kit, had fractured and disconnected from the left anti-torque pedal to the tail rotor control system. The expandable pin connecting the right pedal to the tail rotor control system remained intact and engaged. The operator shipped the pin by commercial carrier to the NTSB Eastern Region Headquarters in Ashburn, Virginia, for further examination as requested, but mislabeled the package with the wrong street address. The carrier shipped the package to a delivery center in Vienna, Virginia, and then redirected the package to a delivery center in San Francisco, California, where it was lost. Consequently, fracture analysis on the fractured pin could not be performed. Photographs of the fracture were not of sufficient quality to perform a visual fracture analysis. The pilot/operator suggested that the accident could have been prevented if the lockout kit were not authorized for use concurrent with the left-hand command kit. A review of the design and materials of the expandable pin by the FAA Aircraft Certification Office responsible for the kit and the kit manufacturer revealed that the pins were designed to replace the "original bolts and are stressed as such." The kit's instructions for continued airworthiness mandated both daily and 300-hour interval inspections for condition and security of the pins.