This caused severe damage to the tail rotor. The AS350 Z contributed to the overall development of the fenestron tail rotor. So, most probably it is a tail rotor malfunction. This is accomplished through a variable-pitch antitorque rotor or tail rotor. The investigation is concentrating on the tail rotor system as a matter of priority. The arrangement allows the helicopter to function without a tail rotor, which saves power. The S-67 featured a five-bladed main rotor and tail rotor. Tail rotor blades are made with both symmetrical and asymmetrical airfoil construction. The tail rotor has only a teetering hinge. About 10% of the engine power goes to the tail rotor. The H160 is the first civilian helicopter to utilise a canted fenestron anti-torque tail rotor. The tail rotor is canted and features a rigid crossbeam. The AH-64 Apache has a four-blade main rotor and a four-blade tail rotor.