Pitch actuation system for a turbine engine propeller, comprising an actuator, a movable part of which is configured to be connected to blades of the propeller so as to rotate them relative to the blade pitch axes (B), comprising: a transmission screw that can rotationally and translationally move along a longitudinal axis (A), a nut, through which said transmission screw passes and which cooperates with this screw so as to translationally displace along the axis (A) with a view to modifying the pitch of the propeller blades, and means for decoupling between the rotation of the propeller and said nut, which is rotationally fixed; first blade pitch control means, which comprise at least one electric motor setting a component into rotation through a planet reduction gear with a view to modifying the position of the transmission screw; second blade feathering means configured to act on the transmission screw with a view to modifying the pitch of the blades if the first means are inactive, and in that said first planet reduction gear comprises a ring gear rigidly connected to said first component, a planet shaft rigidly connected to said first rotor and a planet carrier rigidly connected to said first housing.

Methods and systems for slowing down an aircraft having a propeller. The method comprises operating the propeller at a reference speed with the propeller blades in a first position, applying a load to the propeller to slow down a rotational speed of the propeller when the propeller is in a windmilling state or just before the propeller enters the windmilling state, adjusting the propeller blades to a second position in response to the load being applied, to increase the rotational speed of the propeller back towards the reference speed, and operating the propeller at the reference speed with the propeller blades in the second position.

There is described herein methods and systems for testing a propeller feathering function. The method comprises monitoring a rotational speed over time of propeller blades of an aircraft, commanding an angle change of the propeller blades, comparing a post-angle change rotational speed of the propeller blades to an expected rotational speed without the commanded angle change and obtaining, by the processor, a rotational speed difference, and issuing a test passed signal when the rotational speed difference exceeds a threshold and a test failed signal when the rotational speed difference does not exceed the threshold.

A gas turbine engine including a core having in serial flow order a compressor, a combustor, and a turbinethe compressor, combustor, and turbine together defining a core air flowpath. The gas turbine engine additionally includes a fan section mechanically coupled to the core, the fan section including a plurality of fan blades, and each of the plurality fan blades defining a pitch axis. An actuation device is operable with the plurality fan blades for rotating the plurality fan blades about their respective pitch axes, the actuation device including an actuator located outward of the core air flowpath to, e.g., simplify the gas turbine engine.

Disclosed herein is a fan module with variable pitch blades for a propulsion unit, the fan module comprising a rotor carrying the blades and comprising an inner shaft and an outer casing defining between them a space, a control device for controlling the pitch of the blades, and a feathering device for feathering the blades. The rotation of the rotor is guided by a bearing, and the module further comprises means for recovering and guiding a liquid lubricant of the bearing, with the recovery and guidance means being configured to recover and guide said lubricant from an axial upstream end of the casing, axially from upstream to downstream and radially from the inside to the outside, under the centrifugal effect.

There is described herein the automation of propeller feather testing functions, whereby the test is automatically performed and a pass/fail signal is issued upon completion.

Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45 diameter) footprint.

A bistable pitch propeller includes a ball, a spring, and a clutch module where the clutch module has a range of rotational movement between a locked end position and a released end position. The clutch module includes a detent, where the ball sits inside and outside of the detent when the clutch module is in the locked end position and released end position, respectively. In response to an input torque and a spring force from the spring, the clutch module rotates toward the released end position and the locked end position, respectively. The bistable pitch propeller also includes an aircraft blade where the aircraft blade is at the first pitch angle and the second pitch angle when the clutch module is in the locked end position and the released end position, respectively.

A fan of a turbine engine, the fan including a fan disk provided with blades on its periphery, the blades being pivotally mounted on the disk around a pivoting axis and having a center of gravity, and a pitch change mechanism for the blades, each blade being configured so that its center of gravity is positioned on or at a small distance from a fictitious plane which passes through the pivoting axis of the blade and which is perpendicular to the axis of revolution of the fan when the blade is in a minimum drag position.

A curved body (830), for propelling fluids, crafts and harvesting fluid power, comprises a convex outer leading surface securely connected to a concave inner trailing surface to define an open vessel. Upon oscillation, ambient fluids are accelerated and ejected from the vessel to propel the vessel and the ambient fluids in opposite directions. Apparatus is secured to a motive power source directly or via actuating member (832), by fastening through aperture (834). The oscillating propulsor can be operated directly by a reciprocating motive power source, and indirectly by the reaction momentum imparted to a supporting base. Thrust may be vectored by rotation of the curved body (830) about the supporting base. Drag reduction using fluid dynamic shapes, intake openings, a fore fin (844), an aft fin (846), and a lubricant cavity, are embodied. Enhanced propulsion using multistage oscillating propulsors is embodied.