Abstract: Control surfaces in an aircraft are biparted, and one portion is acted upon by a mechanical signal transmission system in a redundant manner, the other one by an electrical signal transmission system normally operating in parallel; different construction versions and embodiments are described.

Abstract: The invention relates to a measuring device for determining cracks. Light conductive fibers or film are provided as crack detectors in this measuring device which fibers or films are applied directly upon the construction parts. Light is coupled into these light conductive fibers by means of a coupler and the passage of light is monitored at the free end. A fiber fracture serves as irreversible crack indication.

Abstract: A pin extends from the floor near a cargo door and pallets or containers are provided with an attachment which includes a releasable frame with a hinged spring-loaded plate having a bore and runoff surfaces. The bore traps the pin and forces the pallet or container to turn.

Abstract: The supercritical profile has an upper surface whose curvature has two minima, one in front of the mid-chord station, the other one rather close to the trailing edge and having a lower value than the first one. The curvature of the lower surface remains larger beyond the mid-chord station, changes sign and increases to a pronounced maximum not far from the second curvature minimum of the upper surface, and drops to zero at the trailing edge.

Abstract: A method of measuring the rigidity, the damping coefficient and the inertia of a system consisting of a damped, spring-supported mass, particularly, the manually operable member of the control-system of an aircraft or a flight simulator, in which method the measurement of the rigidity takes place by determining the relationship between the force exerted on the mass and the deviation of the mass from the state of equilibrium at a speed and an acceleration of substantially zero value and storing the relationship. The method is characterized by the initial step of forming three electric signals--namely, a force signal having a value directly proportional to the force exerted on the mass, an acceleration signal having a value directly proportional to the acceleration of the mass, and a velocity signal having a value directly proportional to the speed of the mass.

Abstract: Polyester moulding compositions and polyester resins resulting therefrom are rendered fire-protecting by incorporating in the moulding composition a combination of three materials: a source of carbon, such as e.g. pentaerythritol, a source of phosphoric acid, such as e.g. ammonium polyphosphate, and a source of non-inflammable gases such as melamine-formaldehyde, in proportions of 5-20%, 20-40% and 5-20% by weight respectively, calculated on the total weight of this combination plus polyester and monomer.

Abstract: Glass fiber-reinforced epoxy resins are rendered fire-protecting by incorporating in their moulding compositions a combination of three materials: a source of carbon, such as e.g. pentaerythritol, a source of phosphoric acid, such as e.g. a water-insoluble nitrogen-containing polymer phosphate, and a source of non-inflammable gases such as e.g. melamine.

Abstract: An apparatus is disclosed for measuring the electron escape potential (or: Volta potential) of a metal surface. This apparatus comprises a conductive plate to be placed into the vicinity of and parallel to a metal surface under examination in order to form a capacitor; switch means for electrically connecting the conductive plate to a reference potential point; means for subjecting the conductive plate to vibration in a direction vertical to the metal surface; and an external circuit for measuring a measuring potential which is proportional to a current emitted by the capacitor. The conductive plate together with the switch means and part of the vibration-generating means are located in a probe and this probe is connected with the remainder of the apparatus by means of a flexible line which includes the required electric connections.

Abstract: Articles of aluminium or aluminium alloys are pickled by placing them as anodes into a sulfuric acid bath containing no chromic acid or bichromate and connecting them by an electrical circuit including a D.C. potential source to a suitable cathode placed in the same bath, then imposing a certain control voltage from the potential source onto the anode and maintaining the resulting anode voltage at a substantially constant level during the whole pickling period. Means may be provided for continuously measuring the anode voltage and re-adjusting it to keep the voltage constant.