Abstract: A comparative evaluation of a plurality of alternative candidates is performed by creating a plurality of evaluation criteria for evaluating the alternative candidates, comparing pairs of the evaluation criteria and assigning a relative weight to each compared pair of evaluation criteria, assigning an evaluation value to the evaluation criteria for each of the alternative candidates, and generating a relative ranking of the alternative candidates based at least in part on the assigned relative weights and the assigned evaluation values.

Abstract: A method for managing one or more technical performance measure parameters is provided. The method includes defining the one or more technical performance measures parameters and determining, tracking and trending one or more achieved capabilities and one or more projected capabilities of the one or more technical performance measures parameters.

Abstract: A gearbox mounting arrangement for a gas turbine engine includes a controlled spring rate mount that has an appropriate stiffness level to minimize the transmission of loads from the engine case to the gearbox. The controlled spring rate mount is generally T-shaped and includes a cross-member that attaches at the ends thereof to spaced locations on the engine case and a substantially perpendicular leg fixed to the cross-member and having a free end that attaches to the gearbox. The cross-member bends to accommodate the application of vertical loads from the engine case to the gearbox instead of transmitting the loads to the gearbox which would deform the gearbox housing during a high rotor imbalance event.

Abstract: An apparatus for sealing a gap between adjacent rotor blades of a turbine engine rotor assembly and for damping vibrations of the rotor blades is provided. The apparatus comprises a platform seal and a damping block. The damping block is independent of the platform seal and includes apparatus for coupling the platform seal and the damping block. The damping block selectively acts against adjacent rotor blades of the turbine engine rotor assembly, forward of the platform seal, and therefore does not interfere with the platform seal. The coupled damping block and platform seal may be installed in the rotor disc prior to installation of the adjacent rotor blades in the disc, thereby obviating the need to blindly install the platform seal.

Abstract: A nose cone on the fan of a gas turbine engine contains access holes that provide access to cap screws that hold the nose cone on the fan hub. The cap screws extend through an internal flange on the nose cone. A spring clip extends from the flange in a configuration that covers the access hole and holds the cap screw in the flange as the nose cone is installed.

Abstract: An apparatus for sealing a gap between adjacent blades in a rotor assembly for a gas turbine engine is provided. The rotor assembly includes a plurality of blades circumferentially disposed around a disc. Each of the blades includes an airfoil, a root, and a platform extending outward in a lateral direction in a transition area between the root and the airfoil. The disc includes a plurality of complementary recesses circumferentially distributed around the disc for receiving the blade roots. The gaps are formed between edges of adjacent platforms. The platforms collectively form a flow path for primary fluid flow passing by the airfoil side of the platforms and secondary fluid flow passing by the root side of the platforms. The apparatus comprises a thin plate body and apparatus for conducting secondary flow between the thin plate body and root side surfaces of adjacent blade platforms, and thereafter into the gap.

Abstract: A convergent/divergent nozzle (14) has five trains of flaps. Each train is comprised of an inboard (26) and outboard (20) convergent flap, an inboard (48) and outboard (44) divergent flap and an external flap (62). The five external flaps (62) maintain their symmetry while vectoring, whereby overlapping of adjacent flaps is obtained. The inboard and outboard convergent flaps are individually driven (32,36) by a common unison ring (28).

Abstract: A seal centering and restraining device for positioning the seals between the divergent flaps of a vectoring convergent/divergent nozzle. The device includes a restraint bar that spans between two adjacent divergent flaps and is pivotally attached to the air side of a seal and slidably secured by sliders to tracks on the adjacent divergent flaps, thereby sandwiching the adjacent divergent flaps between the seal and sliders. A positioning linkage connecting the two adjacent divergent flaps centers the seal at all nozzle operating conditions.

Abstract: A divergent flap assembly having a divergent flap connected to a sync-ring by first and second divergent struts that cross adjacent the center portions thereof providing a linkage arrangement that produces a uniform vectoring of all of the divergent flaps for a given angle of rotation of the sync-ring about the center thereof.

Abstract: An external flap vectoring mechanism on an axisymmetric gas turbine exhaust nozzle, the external flap vectoring mechanism comprising a plurality of external flaps, each such flap having first and second flaps, the first flap pivotably connected to a sync ring and the second flap pivotably connected to the aft end of the first flap thereby providing for lateral movement of the second flap relative to the first.

Abstract: A sync-ring assembly for use on a axisymmetric gas turbine exhaust nozzle, the sync-ring having a semi-spherical outward surface received within and slidably contacting the cylindrical inner surface of a liner. The sync-ring runs along guide tracks mounted to the case of the nozzle, and is positioned along the liner and rotated with respect to the liner by a plurality of actuators pivotably connected to the sync-ring.

Abstract: Shrouds 22, 24 are welded to support braces 20 near fuel spray ring 12. A splash shield 30 is secured to shroud 22 toward which fuel 16 is sprayed. It extends between braces protecting the shroud 22 from fuel impingement. Cracking of the structure at the shroud-brace interface is avoided.

Abstract: Each convergent flap and seal has a cantilevered extension deflector. This deflector reduces the throat area at minimum throat area, and seals against a divergent flap or seal in the maximum throat area position.Cooling ambient air is induced through openings in the upstream portion of each divergent seal at intermediate throat areas. At minimum throat area the divergent flaps block these openings. At maximum throat area the deflectors block the cooling airflow path.

Abstract: Cooling ambient air is induced through openings in the upstream portion of each divergent flap at intermediate throat areas where the nozzle pressure is below ambient pressure. A barometric damper in these openings prevents outflow of hot gases when operating near the minimum throat area and maximum throat area since the internal pressure is above ambient pressure during such operation.

Abstract: Misalignment tolerances in a nozzle four bar linkage (14, 18, 24, 26) are minimized by direct pinning (42) the A-frame 14 and the mode strut bracket (32). The A-frame and bracket are independently bolted to support 12. Tolerance stackup preventing installation or increasing wear is avoided.