Schweizer 269C Safety Record

The pilot’s failure to adequately inspect the lower coupling driveshaft during his preflight inspection and his non-compliance with an applicable airworthiness directive, which resulted in the failure of the forward drive splines of the lower coupling driveshaft during cruise flight. Co-causal to the accident was the pilot’s failure to maintain control of the helicopter during the autorotation landing.

The separation of the throttle cable’s outer housing from the inner housing at the throttle linkage while at a high-power setting, which prevented the pilot from being able to control the throttle and execute a proper landing flare and resulted in a hard landing.

The helicopter owner’s failure to ensure the helicopter’s airworthiness and the inadequate inspection and maintenance of the helicopter's landing gear dampers, which resulted in ground resonance during throttle application. Contributing to the damage of the helicopter were the improper actions of the pilots after encountering ground resonance.

The student pilot's failure to remove the tension applied to the cyclic before takeoff, which resulted in a loss of directional control and the tail rotor striking the ground.

The non-helicopter-rated pilot's improper decision to operate the helicopter at low-level and his inability to adequately see the horizon over snow and ice, which resulted in controlled flight into terrain.

Ground resonance due to maintenance personnel’s improper inspection of the landing gear dampers, which resulted in the dampers operating outside of allowable limits.

The flight instructor’s inadvertent side-loading of the left skid while demonstrating a running landing, which resulted in a bending overstress fracture of the left skid tube and a subsequent roll-over.

An engine failure due to the separation of the engine crankcase, which resulted from the lateral movement of the center main bearing and the subsequent blocking of the oil feed hole that supplied oil to the No. 2 connecting rod, which then led to its failure due to oil starvation.

The inadequately overhauled landing gear dampers that allowed initiation of a ground resonance event from which the pilot was unable to recover. Contributing to the accident was the overhaul facility's failure to identify the overcharged dampers and a lack of any published acceptance testing criteria for the dampers in the manufacturer's overhaul procedure manual, resulting in the out-of-specification dampers being provided to the operator. Also contributing was the ineffective damper inspection conducted by the operator's maintenance personnel.