FLEXIBLE COUPLING FOR GEARED TURBINE ENGINE

A gas turbine engine (20) includes a fan shaft (72)arranged along an engine central axis, a frame (78) supporting the fan shaft (72), a gear system (48) rotatably coupled with the fan shaft (72), and a flexible coupling (74) at least partially supporting the gear system (48). The flexible coupling (74) defines, with respect to the engine central axis (A), a torsional stiffness TS and a lateral stiffness LS such that a ratio of TS/LS is greater than or equal to about 2.0 to reduce loads on the gear system(48) from misalignment of the gear system (48) with respect to the engine central axis (A).