Abstract: Embodiments of the present application include a variable stator vanes control mechanism for a gas turbine engine. The control mechanism includes a moveable actuation rod in operative communication with a first unison ring such that movement of the actuation rod drives the first unison ring. The control mechanism also includes a bell crank mechanism in operative communication with the first unison ring and a second unison ring such that movement of the first unison ring drives the second unison ring.

Abstract: A turbomachine includes a member formed from a material having a first coefficient of thermal expansion. The member includes a crack. A crack arrestment system is provided in the member. The crack arrestment system includes at least one crack arresting element provided at the crack. The at least one crack arresting element has a second coefficient of thermal expansion that is distinct from the first coefficient of thermal expansion. The at least one crack arresting element is configured and disposed to exert a compressive force on the member at the crack to substantially arrest crack propagation.

Abstract: Embodiments of the present application include a variable stator vanes control mechanism for a gas turbine engine. The control mechanism may include a moveable actuation rod in operative communication with a gear ring such that movement of the actuation rod drives the gear ring. The control mechanism may also include a first plurality of variable stator vanes disposed on a first side of the gear ring, the first plurality of variable stator vanes comprising gear stems in operative communication with the gear ring. Moreover, the control mechanism may include a second plurality of variable stator vanes disposed on a second side of the gear ring, the second plurality of variable stator vanes comprising gear stems in operative communication with the gear ring.