Abstract: A flight simulator includes a servo system connected with a control element, an electrical analog providing inputs to the servo system and receiving inputs from a digital computer and including a combining circuit, a divider and two integrators. Outputs from the two integrators to the computer are of digital form and the second integrator preferably is itself of digital form.

Abstract: Apparatus for reducing mechanical vibrations in a first part of a structure, in which these vibrations occur through its connection to a part of the structure which is the source of the mechanical vibration. This apparatus comprises an electromagnet rigidly connected to the first part of the structure and a body of magnetizable material connected via a resilient element to the first part of the structure, while an air gap is provided between the electromagnet and the body. The electromagnet is energized by a variable current through at least one coil and it exerts an attractive force on said body which is oscillating due to the vibrations occurring in the first part of the structure. The restoring force exerted by the resilient element on the secondary body has the effect of lowering the resonant frequency of the second body on the resilient element as compared to the resonant frequency of the apparatus when no current passes through the coil.

Abstract: Aileron for an airplane wing controlled by a reversible control system. The aileron comprises a first section extending generally behind the pivot axis of the aileron parallel to the longitudinal axis of the wing and a second section extending in front of the pivot axis of the wing to aerodynamically balance the aileron. The second section is coinciding with the wing tip. To improve the transversal stability of the airplane during drifting flight the second section is directed upwards and outwards with respect to the chord plane of the wing at an angle between 20.degree. and 70.degree. with the chord plane.

Abstract: A simulator of previously chosen mechanical properties of the steering system of a device such as an aircraft employs a controllable limiter for simulating the mechanical Coulomb friction of the control member and is arranged in a negative feedback loop and having two control signal inputs which determine the maximum and minimum outputs of the limiter in association with a further input signal corresponding to the friction concerning the control member. The limiter interrupts output until the level of the Coulomb friction to be simulated is exceeded.

Abstract: System for retaining or releasing a number of panels piled onto a supporting structure, such as solar panels of a spacecraft which can be deployed from the piled condition and retracted. The panels each comprise a number of passages at a distance of the edge defining a number of channels through the piled panels. A retainer extending through each channel, comprises operating elements at one side connected to control means attached to the supporting structure and at the other side connected to one or more seizing elements, which under control of said control means and through said operating elements can be moved from a retaining condition in which they seize the outer panel of the pile to a releasing condition in which they do not obstruct the deployment of the panels.

Abstract: Aircraft door of the type which during the flight is pressed all around against the door case under influence of the cabin pressure. During opening and closing the door moves by means of a hinge mechanism with two mutually parallel rotational axes and an intermediate hinge part, one of the rotational axis being connected to the door and the other being connected to the door case. When the door is opened during a first motion phase the intermediate hinge part carries out a rotational movement around the rotational axis connected to the door case whereby simultaneously the angle between the door and the intermediate hinge part is decreased, and thereafter in a second motion phase the intermediate hinge part carries out a rotational movement in the opposite direction around the rotational axis connected to the door case. When the door is closed these movements are carried out with reversed rotational directions and in reverse order.

Abstract: A system for releasing parts of a spacecraft construction that are contained by the use of a tensioned cable, made of a material that will degrade or decompose under the influence of heat, and stretched between two supporting elements of the construction. At least one heating element is connected to an electrical power source mounted into a frame that is attached to the spacecraft structure, in a manner such that the heating element and the opposed cable section are pressed towards each other. The tension in the cable is of sufficient degree to displace the ruptured ends of the cable, when broken, out of contact with the heating element.

Abstract: Sound attenuating structure including a combination of one or more core layers comprising cells directed perpendicular to the main surface of the structure. The core layers are separated from each other by perforated separating sheets, a closed sheet is adhered to one side of said combination and a perforated sheet to the other side of said combination, at which side the sound waves impinge upon the structure. The passages in said last mentioned sheet as well as in the separating sheets have an asymmetric cross section having its smallest diameter somewhat less than the sheet thickness of the structure and increasing from this diameter fluently towards both surfaces of the respective sheet.

Abstract: The invention relates to a convertor for converting electrical vibrations into mechanical vibrations for non-destructive testing of objects, in particular bonded joints between two or more sheets or between sheets and a honey comb structure. Said convertor comprises a polycrystalline, piezo-electric disc, with mutually insulated electrodes on both head faces. The disc is secured in a supporting element by a suspension with a resilient member pressing centrally through a metal pin against the internal head face of the disc. The supporting element is movably installed into a holder such that the supporting element can be moved from a retracted position in the direction of the extended position until such a position is reached that the piezo-electrical disc is pressured against the object to be tested with a predetermined force.The invention also relates to a method for using the convertor.

Abstract: A wing flap assembly, in which each flap (1, 2) has its own suspension and drive mechanism (3-6) and in which two adjacent flaps substantially in line with each other have a part (16) connected for movement with one flap and extending between two abutments (18, 19) on the other flap so that, in case of a failure or disturbance in the suspension and drive mechanism of one flap, this flap is limited in movement with respect to the adjacent flap to avoid serious distorsions and other dangerous consequences of such a failure or disturbance. Preferably the part (16) extending between the abutments is a pivoting lever, so connected to one flap that it moves therewith in a plane substantially parallel to the chord plane (8) of the flaps if one flap moves with respect to the other one.

Abstract: A flight simulating system is provided with a manually operated control member connected to a servomechanism which responds to manual input by the control member and reacts to provide realistic feedback to the control member in accord with simulated flight conditions. For this purpose, a combining circuit, a dividing circuit and two integrator circuits are provided in series. The combining circuit has an input which represents manual input force to the control member and another input from the flight-simulating computer which represents simulated internal forces acting on the controlled member and the dividing circuit divides the output of the combining circuit by a value representing the mass of the control member to produce a control member acceleration-related signal. This acceleration-related signal is integrated twice to produce, respectively, a control member velocity-related signal and a control member position-related signal.

Abstract: Articles of aluminum are pickled by placing them as anodes into a sulfuric acid bath in the absence of chromic acid or bichromate and connecting them by a short-circuit connection to a carbon cathode placed in the same bath. The process also excludes the application of an anodic control voltage.

Abstract: Articles of aluminum are pickled by immersing them into a sulfuric acid bath containing no chromic acid or bichromate but having carbon particles suspended therein. The carbon particles will form tiny electric cells with the aluminum articles at their places of contact and will initiate electrochemical dissolution phenomena there at the point of contact.