A turbine engine is provided that includes a bypass flowpath, a plurality of upstream vanes and a plurality of downstream vanes. The bypass flowpath is fluidly coupled with and downstream of a fan section. The bypass flowpath bypasses a turbine engine core. The upstream vanes are arranged circumferentially about an axis in an upstream vane array. Each of the upstream vanes extends radially across the bypass flowpath. The downstream vanes are arranged circumferentially about the axis in a downstream vane array. The downstream vanes are circumferentially interspersed with the upstream vanes. Each of the downstream vanes extends radially across the bypass flowpath. A first of the downstream vanes is axially offset from a first of the upstream vanes along the axis.

A gas turbine engine arrangement includes an accessory gearbox which is mounted so as to be aligned in an axial direction along the engine. The accessory gearbox may be recessed at least partly into a casing of the engine.

A bearing centering spring includes a cylindrical body with outer rings at each end, wherein each outer ring has outer raceways on the inner surface of the body. There is also a retaining feature on an end of the body and ports through the body that are positioned between the outer rings.

A bearing centering spring includes a cylindrical body with outer rings at each end, wherein each outer ring has outer raceways on the inner surface of the body. There is also a retaining feature on an end of the body and ports through the body that are positioned between the outer rings.

A gas turbine engine has a fan rotor for delivering air axially downstream into a core engine duct, which sequentially passes a turbine, a combustor, and a compressor. The core engine duct extends to a turning supply duct configured to turn the core air flow axially upstream so that the core air sequentially passes through the compressor, combustor and turbine, and into an exhaust conduit which turns the core airflow radially outwardly and axially downstream into an exhaust duct. A door is selectively opened to communicate a portion of the core airflow in the core engine duct to an augmentor with the exhaust duct isolated from the augmentor. The door is at a location prior to the core airflow reaching the compressor. A method is also disclosed.

A method of configuring a plurality of gas turbine engines includes the steps of configuring each of the engines with respective ones of a plurality of propulsors. Each propulsor includes a propulsor turbine and one of a fan and a propeller. Each of the engines is configured with respective ones of a plurality of substantially mutually alike gas generators, with the respective propulsor turbine driven by products of combustion downstream of the gas generator.

A heat shield for protecting a windward side of a vehicle from a high enthalpy flow is disclosed. The heat shield includes a centerbody sidewall and a centerbody base extending aft of the centerbody sidewall. The centerbody sidewall and the centerbody base define a heat shield outer surface that is non-axisym metric. Also disclosed is an aerospike nozzle defined at least partially by the heat shield, an engine including a high pressure chamber and the aerospike nozzle, and a vehicle including the engine.

Aircraft engine rotors traditionally have low coaxiality after assembly. This is solved by the methods and devices described herein, having advantages that the rotors have high coaxiality after assembly, reduced vibration, easy installation, high flexibility, and improved engine performance. A measurement method and device use an air flotation rotary shaft system determining a rotary reference. An induction synchronizer determines angular positioning of a turntable. Using a four probe measurement device, a radial error of a rotor radial assembly surface and an inclination error of an axial mounting surface are extracted and an influence weight value of the rotor on the coaxiality of assembled rotors is obtained. All rotors required for assembly are measured and an influence weight value of each on the coaxiality of the assembled rotors is obtained. Vector optimization is performed on the weight value of each rotor and an assembly angle of each rotor is obtained.

An atmospheric re-entry vehicle includes a main body defining a forward end of the vehicle, a base defining an aft end of the vehicle, and a heat shield at the base. The heat shield includes a heat shield outer surface. The main body and the heat shield are configured such that a centerline of the heat shield is offset relative to a centerline of the main body. At least a portion of the heat shield outer surface is at least substantially axisymmetric relative to the centerline of the heat shield.

Aircraft engine rotors traditionally have low coaxiality after assembly. This is solved by the methods and devices described herein, having advantages that the rotors have high coaxiality after assembly, reduced vibration, easy installation, high flexibility, and improved engine performance. A measurement method and device use an air flotation rotary shaft system determining a rotary reference. An induction synchronizer determines angular positioning of a turntable. Using a four probe measurement device, a radial error of a rotor radial assembly surface and an inclination error of an axial mounting surface are extracted and an influence weight value of the rotor on the coaxiality of assembled rotors is obtained. All rotors required for assembly are measured and an influence weight value of each on the coaxiality of the assembled rotors is obtained. Vector optimization is performed on the weight value of each rotor and an assembly angle of each rotor is obtained.