A vane arc segment comprising: an airfoil fairing having first and second fairing platforms (66, 68) and a hollow airfoil section extending there between; a spar having a spar platform adjacent the first fairing platform and a spar leg that extends from the spar platform and through the hollow airfoil section, the spar leg having an end portion that is distal from the first fairing platform and that protrudes from the second fairing platform, the end portion having a clevis mount; a support platform adjacent the second fairing platform, the support platform having a first through-hole, the end portion of the spar leg extending through the first through-hole such that the clevis mount protrudes from the support platform; and a pin extending through the clevis mount and locking the support platform to the spar leg such that the airfoil fairing is trapped between the spar platform and the support platform, the pin having ends that abut a face of the support platform, the support platform having a second through-hole: the support platform having a tendency to rotate about the pin under the aerodynamic load received from the airfoil fairing; and the vane arc segment further comprising: a stabilizer rod extending through the second through-hole of the support platform and through the hollow airfoil section, the stabilizer rod limiting rotation of the support platform about the pin, wherein the stabilizer rod includes first and second ends (84a, 84b), the first end has a head that is engaged with the support platform at the second through-hole, and the second end is attached to the spar platform. an airfoil fairing having first and second fairing platforms (66, 68) and a hollow airfoil section extending there between; a spar having a spar platform adjacent the first fairing platform and a spar leg that extends from the spar platform and through the hollow airfoil section, the spar leg having an end portion that is distal from the first fairing platform and that protrudes from the second fairing platform, the end portion having a clevis mount; a support platform adjacent the second fairing platform, the support platform having a first through-hole, the end portion of the spar leg extending through the first through-hole such that the clevis mount protrudes from the support platform; and a pin extending through the clevis mount and locking the support platform to the spar leg such that the airfoil fairing is trapped between the spar platform and the support platform, the pin having ends that abut a face of the support platform, the support platform having a second through-hole: the support platform having a tendency to rotate about the pin under the aerodynamic load received from the airfoil fairing; and the vane arc segment further comprising: a stabilizer rod extending through the second through-hole of the support platform and through the hollow airfoil section, the stabilizer rod limiting rotation of the support platform about the pin, wherein the stabilizer rod includes first and second ends (84a, 84b), the first end has a head that is engaged with the support platform at the second through-hole, and the second end is attached to the spar platform.