Composite aerofoils for gas turbine engines are commonly provided with a metal protection strip along the leading edge, to prevent erosion of the leading edge in use and to protect against impacts from foreign bodies. A problem with such strips is that they can cause serious damage to other parts of the engine if they become detached from the aerofoil. The invention provides an aerofoil having such a protection strip, characterized in that the protection strip includes one or more weakening features to reduce the ability of the protection member to withstand a compressive force applied along its length. The weakening features encourage the protection member to break up under impact, or if it becomes detached from the aerofoil, so that damage to other parts of the engine is minimized.