Abstract: Displacements of output portions 35, 36 of a pair of piezoelectric actuators 25, 26 arranged spanwise in a flap drive apparatus are magnified by a displacement magnification mechanism 27 so that a swing arm 28 is driven in swinging fashion with large amplitude. A flap 22 attached to the trailing edge of a blade 21 by way of a connecting rod 30 connected to a tip of the swing arm 28 is driven in vertical angular displacement fashion. The displacement magnification mechanism 27 possesses an eccentric shaft 40 has a first shaft 41 and second shaft 42 with offset axes. An output portion 35 is coupled to the first shaft 41, and an output portion 36 is coupled to the second shaft 42. The swing arm 28 is fixed to the eccentric shaft 40. Displacement of the output portions 35, 36 of the actuators 25, 26 in opposite phase results in a stable swing of the swing arm 28.

Abstract: A flap support mechanism for attachment of a flap to a rotor blade so as to permit angular displacement with respect thereto has a tension-torsion member disposed coaxial with a hinge axis of the flap. One end at the blade root side of the tension-torsion member is secured to the rotor blade. The other end at the blade tip side of the tension-torsion member is secured to the flap. The tension-torsion member is placed such that it passes through a narrow cavity formed at the interior of the rotor blade. Such construction permits smooth flap motion in spite of a large centrifugal force.

Abstract: Upper and lower faces of a helicopter blade aerofoil are defined by the following coordinates. TABLE 1 X/C Yup/C Ylow/C 0.00000 0.00000  0.00000 0.00100 0.00511 −0.00584 0.00250 0.00843 −0.00813 0.00500 0.01218 −0.01014 0.00750 0.01505 −0.01136 0.01000 0.01747 −0.01218 0.01250 0.01959 −0.01277 0.01500 0.02150 −0.01328 0.01750 0.02325 −0.01375 0.02000 0.02487 −0.01415 0.02500 0.02780 −0.01483 0.05000 0.03891 −0.01714 0.07500 0.04682 −0.01862 0.10000 0.05291 −0.01979 0.15000 0.06152 −0.02206 0.20000 0.06666 −0.02470 0.25000 0.06892 −0.02729 0.30000 0.06895 −0.02949 0.35000 0.06841 −0.03109 0.40000 0.06744 −0.03211 0.45000 0.06568 −0.03270 0.50000 0.06301 −0.03272 0.55000 0.

Abstract: A constant speed drive apparatus for an aircraft generator comprises an input shaft for receiving drive torque from an aircraft engine, a traction speed change mechanism of continuously-variable speed change ratio which is coupled to the input shaft, an output shaft for supplying the aircraft generator with drive torque which is changed in speed by the traction speed change mechanism, and a control computer for controlling the speed change ratio of the traction speed change mechanism to maintain the output shaft at a predetermined rotational frequency. With such constitution it is possible to achieve a small and lightweight constant speed drive apparatus having a high transmission efficiency.

Abstract: An actuator and first to fourth links constitute a first displacement magnifying mechanism. An input shaft which is fixed in a basal end of the first and second links, a support shaft which is fixed in a basal end of the third and fourth links, and a displacement magnifying lever constitute a second displacement magnifying mechanism. In the displacement magnifying lever, an intermediate portion is angularly displaceably coupled to a tip end of the support shaft, a tip end of the input shaft is angularly displaceably coupled to one end, and an output rod is angularly displaceably coupled to another end. The expansion and contraction of the actuator are magnified by the first and second displacement magnifying mechanisms so as to drive a flap angularly via output rod. According to this configuration, the displacement of the actuator can be largely magnified so that the flap can be sufficiently angularly displaced in the vertical direction and in a reciprocal manner.

Abstract: A flight path display apparatus provided in a cockpit of an aircraft has a head-up display unit. An image combining panel of the head-up display unit displays a flight path image projected from projecting system which is superimposed on the outside view. Computing system for calculating the image to be projected to the image combining panel calculates a display position of the target flight path based on data from storage system in which predetermined flight paths are stored and from aircraft flight data measuring system for measuring the position and attitude of the aircraft. When the display position of the target flight path is outside a display area of the image combining panel, a target mark indicative of a direction toward the flight path from the center of the display area blinks on the image combining panel. With the above construction, a flight path display apparatus which allows a pilot to keep sight on a target flight path is realized.

Abstract: In a variable mode of operation in which clutches are locked and a clutch and a brake are unlocked, the power of an input shaft is branched to a traction transmission mechanism. By contrast, in a fixed mode of operation in which the clutches are unlocked and the clutch and the brake are locked, the power of the input shaft is not branched to the traction transmission mechanism. In this way, the fixed mode and the variable mode are selectively used, whereby noise reduction and enhanced fuel efficiency can be attained. According to this configuration, it is possible to provide a power transmission apparatus for helicopters in which the number of rotations of a main rotor or a tail rotor is continuously varied while maintaining the number of rotations of an engine constant.

Abstract: The root end is attached to the rotor head for rotationally driving. The central portion has aerodynamic characteristics depending on the leading and trailing edges and which extend linearly from the root end in parallel to each other, and the chord dimension therebetween. A planform shape of the blade tip portion is defined by the first leading edge which extends forwardly as the distance from the outboard end of the leading edge of the central portion outwardly increases, the second leading edge and the side edge which are rearwardly swept as the distance from the outboard end of the first leading edge toward outboard side outwardly increases, the first trailing edge which is curved forwardly as the distance from an outboard end of the trailing edge of the central portion outwardly increases, and the second trailing edge which is swept rearwardly as the distance from the outboard end point of the first trailing edge outwardly increases.

Abstract: A low-noise level landing apparatus for helicopters comprises a helicopter position calculator for calculating the position of the helicopter, a data input device, an air data sensor for measuring an airspeed and a descending angle, a rotor tachometer for detecting a rotor rotational speed, a memory and a fuel gauge for calculating the weight of the helicopter, a rotor rotational speed controller for controlling the rotor rotational speed, a BVI noise generating area database device for storing noise levels in accordance with parameters of descending speed, airspeed, descending angle, rotor rotational speed and weight of the helicopter. A computer selects a flight route, an airspeed, a descending angle and a rotor rotational speed wherein noise is reduced, by setting a plurality of flight routes on the basis of the helicopter position and landing point and by referring to the noise generating area database device. Low-noise level landing is then carried out by pilot manual control or automatic flight control.

Abstract: A blade root portion of a rotor blade is attached to a rotor head for rotating. A center portion linearly elongates from the blade root portion. A blade tip portion outward elongates from the center portion and has a shape which is defined by a leading edge, a side edge and a trailing edge, and has a predetermined aerofoil. In the leading edge of the blade tip portion, a swept-back angle &lgr;(r) at a distance r from the rotation center of a rotor satisfies relational expression (1) of a rotor blade length R of a rotorcraft, a maximum flight Mach number M∞ which is a flight limit speed of the rotorcraft, a blade tip Mach number MTIP which is a tip speed during hovering, and a drag divergence Mach number Mdd which is determined from the aerofoil of the blade tip portion.

Abstract: Upper and lower surfaces of an aerofoil are defined by the following coordinates given in the table below, and the configuration of a leading edge of the aerofoil is defined by the following leading edge radius and the center of circle. Thus drag divergence Mach number Mdd and maximum lift coefficient Clmax can be increased and the noise level can be reduced.______________________________________ X/C Yup/C Ylow/C ______________________________________ 0.00000 -0.00323 -0.00323 0.00100 0.00155 -0.00758 0.00250 0.00418 -0.00925 0.00500 0.00782 -0.01062 0.00750 0.01060 -0.01155 0.01000 0.01312 -0.01213 0.01750 0.01912 -0.01316 0.02500 0.02381 -0.01388 0.05000 0.03437 -0.01561 0.75000 0.04070 -0.01707 0.10000 0.04466 -0.01852 0.15000 0.04893 -0.02100 0.20000 0.05083 -0.02312 0.25000 0.05150 -0.02506 0.30000 0.05149 -0.02663 0.35000 0.05105 -0.02775 0.40000 0.05016 -0.02835 0.45000 0.04875 -0.02839 0.50000 0.04663 -0.02767 0.55000 0.04359 -0.02618 0.60000 0.03974 -0.02407 0.65000 0.03515 -0.02146 0.70000 0.

Abstract: A flap is attached to a rear end of a blade so as to be angularly displaceable. Displacement magnifying means magnifies the amount of displacement from an actuator to drive the flap. An input portion to which the displacement is applied from the actuator is expandably and contractibly supported by bellows. Likewise, an output portion to which the input amount of displacement is magnified is expandably and contractibly supported by a bellows. Consequently, displacement magnifying means is realized in which, compared with a existing piston with O ring which slides on the cylinder inner wall, no deterioration in response characteristic due to high friction occurs when the actuator is displaced at high speed, and no fluid leakage due to deterioration or wear of the O ring occurs. According to this structure, a rotor blade flap driving apparatus is obtained which has displacement magnifying means with fast response and no fluid leakage.

Abstract: A main rotor torque compensation apparatus for a helicopter having a main rotor and a tail rotor includes vertical tails that are supported at a variable angle of attack. An actuator adjusts the angle of attack such that the main rotor torque is compensated by the torque of the tails together with the torque of the tail rotor.

Abstract: The coordinates defining the upper surface, lower surface, leading edge configuration and center of circle for a helicopter blade airfoil are given to increase maximum lift coefficient and lift-to-drag ratio, and to reduce noise level.

Abstract: In a helicopter blade aerofoil, upper and lower surfaces thereof are defined by the following coordinates, and the leading edge profile of the aerofoil is defined by the following leading edge radius and center of circle. Thus drag divergence Mach number Mdd and maximum lift coefficient Clmax can be increased and the level of noise can be reduced.______________________________________ X/C Yup/C Ylow/C ______________________________________ 0.00000 0.00000 0.00000 0.00250 0.00781 -0.00558 0.00500 0.01131 -0.00765 0.00750 0.01423 -0.00874 0.01000 0.01660 -0.00964 0.01750 0.02224 -0.01156 0.02500 0.02658 -0.01276 0.50000 0.03585 -0.01568 0.07500 0.04128 -0.01758 0.10000 0.04480 -0.01901 0.15000 0.04893 -0.02113 0.20000 0.05095 -0.02306 0.25000 0.05181 -0.02492 0.30000 0.05200 -0.02647 0.35000 0.05179 -0.02760 0.40000 0.05129 -0.02821 0.45000 0.05038 -0.02827 0.50000 0.04888 -0.02775 0.55000 0.04673 -0.02662 0.60000 0.04393 -0.02491 0.65000 0.04037 -0.02268 0.70000 0.03592 -0.01996 0.75000 0.03052 -0.01682 0.

Abstract: Each engine is directly coupled to an engine deceleration device composed of a traction speed change mechanisms and a planetary speed change mechanism, and is decelerated at a desired speed change ratio, and rotate and drive a collector gear and a main rotor shaft. The collector gear rotates and drives accessories and a tail rotor through a second traction speed change mechanism changing speed in inverse number of the speed change ratio of the traction speed change mechanisms. Thus, the rotating speed of the engines can be continuously decelerated at an arbitrary speed change ratio, and an engine deceleration device of small size, light weight, and low loss is realized. At the same time, a power transmission device for helicopters capable of changing the rotating speed of the main rotor at a constant engine rotating speed is realized.

Abstract: A control system has an HHC actuator having a basal portion and a movable portion. A load acting on the control system is detected by a semiconductor gauge. The load detected by the semiconductor gauge is compared with a threshold value in a computer. If the detected load is larger than the threshold load, the movable portion is fixed to the basal portion by a fixing mechanism. By detecting the sign of stall of blades, the HHC actuator is fixed in a neutral position, allowing safe flight. A fixing switch is provided for allowing the fixing mechanism to operate regardless of the result of the comparison with the computer.

Abstract: A blade of the rotor is attached to a main rotor shaft, and is rotated counterclockwise at a high speed when viewed from above. In the vicinity of the blade tip, a flap having a wing shape in section is pivotally supported with a hinge so as to be angularly displaceable and at the end a part of the rear end of the blade is cut out. A hinge line which indicates the center of the angular displacement of the hinge is formed so as to be parallel to a straight line passing through the rotation center of the rotor and the center of gravity of the flap. A helicopter rotor equipped with flaps is provided in which the influence of the centrifugal force acting on the center of gravity of a blade can be largely reduced, and a flap control mechanism can be reduced in size and weight.