Patent ID: 8219266

Claim:
A method for attenuating lateral effects on an aircraft due to turbulence encountered by the aircraft during flight, the method comprising the steps of: a) estimating, by a roll moment estimator, a roll moment of the aircraft due to wind; b) measuring current values of first aircraft parameters; c) calculating, by a calculating unit, based on said estimated roll moment and said measured current values, the following: a roll control order to control at least one first controllable movable member to act on aircraft roll, said roll control order applied to said first movable member to minimize aircraft roll-wise disturbances due to wind; and a yaw control order to control at least one second controllable movable member to act on aircraft yaw; wherein: said roll control order is applied to said first movable member, said yaw control order is applied to said second movable member, and in step c): said roll and yaw control orders are calculated based on a sideslip value representing sideslip value of the aircraft due to the wind; and said yaw control order is calculated as a function of said roll control order so that said yaw control order compensates for aircraft lateral effects due to turbulence and lateral effects due to application of said roll control order to said first movable member, wherein in step a), to estimate said roll moment due to the wind: a global roll moment DCl is determined with the aid of the following expression: DCl=ΔL /(ρ· V 2 ·S·co/ 2) in which: ΔL is a coefficient which is calculated on the basis of measured values of parameters of the aircraft; ρ is the density of the air; V is the air speed of the aircraft; S is the surface area of the airfoil of the aircraft; and co represents the mean aerodynamic chord of the aircraft; a roll moment ΔClδl which is engendered by the current control of movable members of the aircraft, which act on the roll, is determined; and said roll moment ΔClW is calculated with the aid of the following expression: Δ Clw=DCl−ΔClδl.