Abstract: A gas turbine engine includes a plurality of blades, a sensor configured to detect vibration on one or more of the plurality of blades, and a controller coupled to the sensor and configured to adjust a blade incidence upon an onset of vibration being detected by the sensor wherein the adjustment of the blade incidence reduces the vibration.

Abstract: A gas turbine engine rotor stack includes one or more longitudinally outwardly concave spacers. Outboard surfaces of the spacers may be in close facing proximity to inboard tips of vane airfoils. The airfoils have dihedral and sweep.

Abstract: A variable area fan nozzle for use with a gas turbine engine system includes a nozzle section that is movable between a plurality of positions to change an effective area associated with a bypass airflow through a fan bypass passage of a gas turbine engine. A protective coating is disposed on the nozzle section and resists change in the effective area of the nozzle section caused by environmental conditions.

Abstract: A gas turbine engine rotor stack includes one or more longitudinally outwardly concave spacers. Outboard surfaces of the spacers may be in close facing proximity to inboard tips of vane airfoils. The airfoils have dihedral and sweep.

Abstract: A flow directing element, such as a vane for a turbine engine compressor, has a variable chord to improve compressor surge margin without compromising compressor efficiency. The vane has an airfoil section (70) with a leading edge (80), a trailing edge (82), a root (84) and a tip (88). The chord of the airfoil generally increases from a first value at the root to a second larger value at a part span location (110) intermediate the root and the tip so that when the airfoil is installed in a compressor, the location of the trailing edge becomes closer to the compressor discharge as the spanwise distance from the root increases. The chord is generally constant from the part span location to the tip.