AMC E 520(c)(1) Strength - Shedding of Blades

(1)In order to reduce the risk of a single blade Failure leading to a multiple blade Failure and possible non-containment, particular attention should be paid to such items as blade material, blade root fixing and the design of casing joints in vulnerable areas.

(2)In providing containment for compressor and turbine blades account should be taken of the possibility that the final trajectory of a failed blade may not be directly in the plane of its rotation. This is particularly important when the final containment provisions are external to the Engine casing and lie some distance from it (impact points on the aircraft structure of failed blades have been experienced at angles up to ± 30° from the point of intersection of the Engine centre line and the plane of rotation) or where the Engine casing containment capability is reduced adjacent to the plane of rotation of the blades, e.g. by virtue of cut-outs for adjacent stator roots, bleed ports, etc. This AMC is not meant to impose an obligation on the Engine constructor to provide containment in the direction of the intake and exhaust, provided the limits of the angles to which containment is assured are made available to the aircraft constructor installing the Engine.

[Amdt. No.: E/1]