Rotary wing drone comprising a collapsible drone structure

A rotary wing drone comprising at least one rotor carried by a drone structure, wherein the drone structure comprises:

• a drone body and at least two groups of arms, each group of arms comprising a plurality of arms and an axis of rotation that is separate from the axis of rotation of each other group of arms, and wherein each arm of each group is rotatably mounted on the drone body about the axis of rotation of said group of arms between a deployed position for flight and a folded position for transport;
• and
• an articulation system for each group of arms which comprises an articulation assembly associated with each arm of each group of arms, wherein each articulation assembly is configured to lock the associated arm selectively in the deployed position and the folded position, wherein each articulation assembly comprises:
• a first locking member and a second locking member configured to engage with one another to prevent the rotation of the associated arm relative to the drone body and to disengage from one another to allow rotation of the associated arm relative to the drone, wherein the first locking member and the second locking member engage with, and disengage from, each other by axial translation along the axis of rotation;
• and
• an elastic return member configured to return the first locking member and the second locking member into engagement with one another.