Abstract: A gas turbine engine includes rotor blades including airfoils that facilitates reducing manufacturing losses due to airfoil trailing edge scarfing. Each airfoil includes a first and second sidewall connected at a leading edge and a trailing edge. The sidewalls define a cooling cavity that includes at least a leading edge chamber bounded by the sidewalls and the airfoil leading edge, and a trailing edge chamber bounded by sidewalls and the airfoil trailing edge. The cooling cavity trailing edge chamber includes a tip region, a throat, and a passageway region connected in flow communication such that the throat is between the tip region and the passageway region. Furthermore, the tip region is bounded by the airfoil tip and extends divergently from the throat, such that a width of the tip region is greater than a width of the throat.

Abstract: A method is provided for repairing a surface portion of an article including a metallic environmental resistant coating on a substrate. The coating includes a coating outer portion bonded with the substrate through a diffusion zone that includes at least one feature, for example Al and/or an intermetallic phase, in an amount detrimental to application of a metallic replacement coating and/or repair of the article. The method comprises removing the coating outer portion to expose a surface of the diffusion zone. The substrate and the diffusion zone are heated at a temperature and for a time sufficient to diffuse and/or dissolve at least a portion of the at least one feature in the exposed surface and in a portion of the diffusion zone beneath the exposed surface to a level below the detrimental amount. This provides a replacement surface portion integral with diffusion zone. Then a metallic replacement coating outer portion is applied to the replacement surface portion.

Abstract: A gas turbine engine includes rotor blades including airfoils that facilitates reducing manufacturing losses due to airfoil trailing edge scarfing. Each airfoil includes a first and second sidewall connected at a leading edge and a trailing edge. The sidewalls define a cooling cavity that includes at least a leading edge chamber bounded by the sidewalls and the airfoil leading edge, and a trailing edge chamber bounded by sidewalls and the airfoil trailing edge. The cooling cavity trailing edge chamber includes a tip region, a throat, and a passageway region connected in flow communication such that the throat is between the tip region and the passageway region. Furthermore, the tip region is bounded by the airfoil tip and extends divergently from the throat, such that a width of the tip region is greater than a width of the throat.

Abstract: A fluid powered actuator system includes two identical fluid powered actuators operable by respective supply pressures which are controlled by respective identical valve arrangements. Operating positions of flow control elements of the valve arrangements are applied through respective couplings to a differential arrangement which operates, if these positions differ by an unacceptable amount, to apply an error indication through respective coupling to prevent the supply pressures from being applied to the respective actuators.