Method of protecting a margin for controlling the yaw attitude of a hybrid helicopter, and a hybrid helicopter

A method of protecting a margin for controlling the yaw attitude of a hybrid helicopter, the hybrid helicopter including a lift rotor arranged above a fuselage as well as at least one first propeller and at least one second propeller placed on either side of the fuselage, the hybrid helicopter having a thrust control configured to generate at least a first order or a second order for modifying a first pitch of first blades of the first propeller and a second pitch of second blades of the second propeller, the hybrid helicopter having a yaw control configured to modify the yaw attitude of the hybrid helicopter by increasing the first pitch of the first blades and by reducing the second pitch of the second blades,

• wherein the method includes a protection phase comprising the following step:
• after the first order has been issued for increasing the first pitch and the second pitch, having a control computer inhibit the first order when the hybrid helicopter reaches an operating point for which a yaw attitude control margin is less than or equal to a threshold and/or for which a prediction of the yaw attitude control margin that will be reached within a predetermined time interval is less than or equal to the threshold.