Flexible support structure for a geared architecture gas turbine engine

摘要

A gas turbine engine includes a fan shaft (76) and a support (82) which supports the fan shaft (76). The support (82) defines a support lateral stiffness. A gear system (60A) drives the fan shaft (76). A flexible support (78) at least partially supports the gear system (60A), and defines a flexible support lateral stiffness with respect to the support lateral stiffness. An input (62) to the gear system (60A) defines an input lateral stiffness with respect to the support lateral stiffness. A method of designing a gas turbine engine is also disclosed.