Question

Which of these options is a feature of teetering rotor blade?

(a) Two blades attached to hub without flap/hinge

(b) Three blades attached to hub with only flaps

(c) Two blades attached to hub with single flap hinge

(d) Four blades attached directly to hub

The question was asked during an interview.

This intriguing question originated from Blades and Propellers topic in chapter Helicopter Dynamics of Aerodynamics

Answer 1

The correct answer is (a) Two blades attached to hub without flap/hinge

The best I can explain: Teetering rotor is a type of rotor in which two blades are directly attached to the hub rigidly without any flaps or hinge unlike articulated rotor which makes use of both. The two blades make one complete structure which flaps relative to the shaft.