The helicopter accident that killed the president of Leicester City and four other people was caused by a pin that was released in the tail rotor control mechanism, a report revealed.
The air accident investigation branch found that the pin was disconnected and that the helicopter became unstable and prevented the pilot from controlling it.
10/31/18 Expert analysis in collision of helicopters from Leicester
The president of the city of Leicester, Vichai Srivaddhanaprabha, two of his employees, Nursara Suknamai and Kaveporn Punpare, pilot Eric Swaffer and Swaffer Izabela Roza Lechowicz's girlfriend died when the plane crashed in a parking lot near the King Power stadium on October 27.
The president of Leicester, Vichai Srivaddhanaprabha, was among five people killed in the accident
The researchers found that the pedals of the pilot were disconnected from the rotor in the tail and caused the plane to make an uncontrollable right turn before it swore and fell, reaching the ground in a ball of flames. The pedals and the tail rotor are connected by a mechanism that failed after the parts of it disconnected and there was a "black fat accumulation" in a component.
Victims in the clockwise direction of the top left: Eric Swaffer, Izabela Roza Lechowicz, Kaveporn Punpare and Nursara Suknamai
The failure caused the passage of the tail rotor blades to change "until they reached the physical limit of their travels," the researchers said. The report stated: "The cause initiator and the exact sequence of the failure that resulted in the loss of the tail rotor control is being investigated as a priority."
The report said: "The axis of control of the actuator of the tail rotor disconnected from the mechanism of the actuator lever." The disconnection stopped working the feedback mechanism so that the tail rotor actuator worked and the tail rotor actuator did not respond to the yaw control inputs. "This loss of the feedback mechanism meant that the yaw stops were ineffective and tail rotor actuator was able to continue changing the pitch of the tail rotor blades "until they reached the physical limit of their travel." "This resulted in an uncontrollable right."
He continued: "The force and the sufficient torque were applied to the chestnut nut on the end of the actuator of the control shaft until the friction that adhered to the pin support and cut the split pin installed." While the spindle was rotating and a distorted control The input was applied, the axle "unscrewed" the nut, disconnecting the axis of the actuator level mechanism and causing the nut to be welded to the pin holder. "
He added: "The threaded portion of the control shaft at the end of the actuator was inside the outer axle and contained the remains of the split pin. The upper and lower part of the split pin had been rotated.Leave a comment