Abstract: This invention relates to a self-degradable optical fiber, that is to say, an optical fiber that contains, within its own structure, compounds capable of leading to its degradation. This optical fiber comprises a core, a sheath and a polymer coating, in which at least one calixarene is incorporated in the coating, the calixarene(s) imprisoning at least one compound capable of being released under defined conditions of temperature and/or humidity and/or irradiation and of bringing about degradation of the coating. The invention also relates to a method of preparing this fiber and a wire guided device comprising this fiber.

Abstract: A control system for hydraulically controlling variable engine structures is disclosed in which the control system utilizes hydraulic fluid identical to that used by the aircraft hydraulic control circuit. A high pressure hydraulic pump, driven by the aircraft engine, may be interconnected with the aircraft hydraulic control circuit, or may be associated with a separate fluid reservoir, to supply pressurized hydraulic fluid to the actuators for controlling the variable engine structures. The engine control circuit also includes a hydraulic pressure modulator to modulate the pressure of the fluid supplied to the actuator and a selector connected between the high pressure pump and, the modulator and the aircraft control circuit to selectively supply the high pressure hydraulic fluid from the pump to either the engine control circuit, or to the aircraft control circuit.