An aircraft rotor blade includes a surface of the rotor blade, at least one main hole that extends through the surface and has a width and a length, and at least one leader hole that extends through the surface and has a length that is less than the length of the main hole and arranged spaced from and adjacent the main hole. The leader hole gradually increases in width from a first end of the leader hole opposite the main hole to an opposed second end of the leader hole proximate the main hole to operatively gradually distribute stress in the leader and main holes and rotor blade and reduce an amount of the stress exerted therein.

The application relates to a wireless rotating instrumentation package for collecting data from a spinning rotor head of a rotary wing aircraft. The application also relates to a method of wirelessly collecting data from a spinning rotor head of a rotary wing aircraft.

A flight system for an aircraft and method for controlling a clearance between a first rotor disk and a second rotor disk of an aircraft is disclosed. The flight system includes a sensor for measuring an angle of deviation of at least one of a first rotor disk and a second rotor disk of the aircraft to indicate a clearance between the first rotor disk and the second rotor disk as well as sensors for measuring a flight condition of the aircraft. A control allocation module uses the measured angle of deviation and the flight condition of the aircraft to determine an allocation of control settings to axis-controlling devices of the aircraft to attain a selected pitch of the aircraft, wherein the allocation is based at least on the measured angle of deviation and the flight state of the aircraft.

A helicopter rotor blade performance system (BPS) allows for accurate determination of blade track height and blade track phase while reducing size, weight, and complexity of the system. The BPS uses sensing technology that is scalable to adapt to a variety of helicopters and is readily and unobtrusively installed. The BPS includes a bused smart system methodology that can directly measure track height, while phase can be estimated using the time synchronous average of the magnitude or range of the return signal from a radar wave. The BPS includes a rotation monitor, radar tracker, and control unit, that allows for a determination of the track errors and consequentially whether a track rebalancing should occur.

A balance weight assembly for a rotor blade of a rotorcraft. The balance weight assembly includes a balance weight pocket formed by a balance weight tray and a cover. The balance weight tray has an upper surface including a lip region extending outwardly from a projected region with an outboard boss. A balance weight receiving cavity is recessed from the upper surface and contains a plurality of balance weights. The projected region is disposed within an opening in a hollow blade spar such that the outboard boss of the balance weight tray has a contact relationship with an outboard surface of the opening. The cover is coupled to the balance weight tray such that the lip region of the balance weight tray and at least a portion of the cover have a clamping relationship with the blade spar, thereby coupling the balance weight pocket to the blade spar.

A measurement device for measuring the angular positions of a blade element of a rotorcraft, the blade element being arranged to be movable relative to a hub of a rotor in pivoting about at least one pivot axis. The invention also relates to a rotorcraft fitted with such a measurement device and to a corresponding measurement method.

The present invention relates to a wind turbine rotor balancing method which compensates imbalances between the centres of gravity of the wind turbine blades, in both magnitude and position along said blades, so that the amount of mass needed to carry out this balancing method is minimized, while reducing the loads and vibrations associated with a position of the centre of gravity of the rotor not aligned with the axis of rotation thereof, wherein the invention further relates to the wind turbine rotor balancing system and the wind turbine balanced with the above method.

A rotor system has a rotor, an axis of rotation about which the rotor may be rotated, a linkage system having a first adjustable length portion and a second adjustable length portion, wherein the second adjustable length portion is configured to provide a relatively finer adjustment of an overall effective length of the linkage system as compared to the first adjustable length portion and wherein the rotor is configured to rotate about the axis in response to changing the overall effective length of the linkage system.

A method and system for vector limiting of a rotor control volume for a helicopter with one or more controllers configured to issue a displacement command during a flight maneuver and a computer operably connected to the one or more controllers and configured to receive signals with a processor indicative of a displacement command for a rotor during a flight maneuver; determine with the processor an origination point for a command vector in a reference frame; determine with the processor the command vector in the reference frame; determine with the processor a command radius for the command vector; compare with the processor the command radius with values of estimated command radii in a look-up table; and determine with the processor a control volume limited command in response to the comparing of the command radius with the estimated command radius.

Tracker systems are disclosed, the system mountable on a device having one or more rotary component, comprising: an optical tracker having circuitry that causes the optical tracker to transmit one or more optical signal to be deflected by, and received back from, the one or more rotary component of the device, the optical tracker having circuitry transmitting data indicative of a distance; an orientation/motion sensor having circuitry that automatically determines data indicative of the orientation and motion of the optical tracker; and one or more computer processor that utilizes the optical tracker determined distance and the orientation/motion sensor data to determine track error of the one or more rotary component of the device, and transmits data indicative of the track error.