FAA 2023-17-51 (Emergency)

Requires a one-time inspection for tail rotor blade skin to core voids and replacement of tail rotor blades found with voids exceeding the limits. Prompted by an operator reporting to Bell that, while manually rotating the tail rotor blade, one of the blades had an abnormal sound. The operator then performed a tap test, which indicated a debonded area. Bell’s investigation revealed that 43 of the tail rotor blades manufactured could potentially have adhesive missing between the upper skin and the core. Voids and lack of adhesive between the tail rotor blade skin and core could result in severe vibration and in extreme cases, subsequent failure of the tail rotor blade and loss of tail rotor control.