A turbofan engine for an aircraft includes a fan and a fan actuation system. The fan has a plurality of fan blades coupled to a fan shaft having one or more fan bearings. The fan blades are rotatable about a pitch axis. The fan actuation system is disposed within a fan hub and includes one or more actuators for rotating the fan blades about the pitch axis and one or more radial thrust bearings. The fan actuation system is characterized by a fan actuation system length envelope in a range from 8.5 to 24 and given by

[00001]$\frac{N_{\mathrm{FB}}{D}_{\mathrm{FT}}}{L_{\mathrm{AXIAL}}\left(\frac{R_{\mathrm{TB}}}{N_{\mathrm{FB}}}\right)}.$

N.sub.FB is a number of the fan blades, D.sub.FT is a fan tip diameter of the fan blades, R.sub.TB is a thrust bearing radius of the radial thrust bearings, and L.sub.AXIAL is an axial length from a fan hub tip to the fan bearings.

An assembly for a turbine engine includes a ring with a rotationally symmetrical axis. The assembly further includes a plurality of support sleeves, each having a rotationally symmetrical axis and configured to receive a stud of a variable pitch blade. Each support sleeve includes a bore passing right through the support sleeve along the rotationally symmetrical axis. Each support sleeve is mounted on the ring so as to pivot about a pivot axis transverse to the radial axis and to the rotationally symmetrical axis.

A gas turbine engine includes a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order. A fan defining a fan axis and comprising a plurality of fan blades is rotatable about the fan axis. A pitch change mechanism is operable with the plurality of fan blades to control a pitch of the plurality of fan blades. A counterweight is connected to each respective fan blade. A spring mechanism is operably associated with each fan blade of the plurality of fan blades to create a spring twisting moment on the respective fan blade that is counter to a centrifugal twisting moment of the respective fan blade.