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公开(公告)号：CA1091213A
公开(公告)日：1980-12-09
申请号：CA297067
申请日：1978-02-13
Applicant: UNITED TECHNOLOGIES CORP
Inventor： JOHNSON RAYMOND G JR , COTTON LOUIS S , VERZELLA DAVID J
Abstract: VARIABLE INCIDENCE HELICOPTER STABILATOR AND FAIL SAFE ACTUATOR A helicopter stabilator, combining the functions of tail stabilizer and aircraft elevator, has its angle of incidence with respect to the helicopter controlled by means of a pair of reversible electric jack-screw type actuators acting in series, each being controlled in a closed-loop fashion by separate electronic hardware, the position of each as well as the rate of change thereof being compared with the other, the controls being disconnected when the actuators fail to track within a threshold disparity of either position or rate of change of position of each other, whereby catastrophic aerodynamic changes, which could otherwise occur from electronic or actuator failure, are avoided, but dynamic loads do not cause unnecessary failure indications. A test switch introduces an imbalance to test the fault circuitry. The stabilator is biased to assume a maximum incidence position so as to be insensitive to the substantially vertical component of main rotor downwash, at low speeds, including hover; and inputs from airspeed and collective pitch position cause it to assume a substantially level position at higher, cruise speeds, for maximum forward flight stability. A pitch rate gyro input controls the stabilator for stable flight against pitch-inducing flight commands and external effects, such as gusts. In one embodiment, the electronic controls are related to a canted tail rotor which not only provides directional stability, but also provides tail lift; to overcome tail-up and tail-down effects of the downward component of the tail rotor due to more or less thrust and real or apparent lateral accelerations, a lateral accelerometer is used. To avoid main rotor downwash against the stabilator at hover, the lateral accelerometer and collective pitch inputs are washedout at low speeds. The bias allows final adjustment for high speed flight. The invention disclosed herein was made under or in the course of a contract with the Department of the Army.
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公开(公告)号：CA1073074A
公开(公告)日：1980-03-04
申请号：CA271673
申请日：1977-02-14
Applicant: UNITED TECHNOLOGIES CORP
Inventor： COTTON LOUIS S
Abstract: The factors (including collective pitch, weight, altitude density, rotor speed and airspeed) which determine the extent to which the rotor of a helicopter may be loaded, are fed into a look-up table, and the permissible acceleration normal to the rotor is compared against actual acceleration normal to the rotor, an alarm signal resulting whenever the actual exceeds the permissive; the alarm signal may be utilized to shake the collective stick so as to simulate pre-overload vibration as a warning to the pilot. The invention disclosed herein was made in the course of or under a contract with the Department of the Army.
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公开(公告)号：DE2715691A1
公开(公告)日：1977-12-22
申请号：DE2715691
申请日：1977-04-07
Applicant: UNITED TECHNOLOGIES CORP
Inventor： COTTON LOUIS S
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公开(公告)号：CA1072195A
公开(公告)日：1980-02-19
申请号：CA239974
申请日：1975-11-18
Applicant: UNITED TECHNOLOGIES CORP
Inventor： BARNUM RONALD E , COTTON LOUIS S , TEFFT FRANKLIN A
Abstract: To prevent inadvertent ground contact of the tail of a helicopter during a landing operation without providing a continuous warning signal for normal landings the altitude and attitude signals are scaled such that when they are equal and opposite in voltage and phase compared to a ground contact curve the comparator will energize a relay for actuating a pilot warning signal. A rate of descent signal biases the altitude signal upward varying in proportion to rate of descent as to enable the pilot to have sufficient warning time to take corrective action.
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