Abstract: An inertial sensing system includes a geometric structure having several independent mechanically resonant modes of vibration such that when the structure is subjected to outside inertial motions that are to be sensed, a driven mode of vibration will couple energy in a specific manner into a pickup mode. The driven mode serves as a reference motion. The system measures angular rotation rate by sensing the vibrations in the pickup mode caused by the action of the Coriolis effect on the balanced driven mode which couples energy into the pickup mode. The system includes a portion of the geometric structure that is subject to strain caused by linear acceleration in one direction. The strain introduces an imbalance in the driven mode which causes energy to be coupled to the pickup mode of vibration in a nominally linear manner. A sensing circuit is provided to sense the amount of energy coupled into the pickup system as a measure of applied angular rotation and applied acceleration.

Abstract: An apparatus provides lightning protection for the radome of an aircraft, or the like, by providing an electrically discontinuous path having a plurality of separated electrically conductive segments that upon exposure to a high voltage field, form an inonization channel in the air above the segments. The conductive segments are so formed that the gap separating adjacent segments is narrower along the outer, exposed surfaces of the segments than is the case between surfaces of the adjacent segments anchored to a dielectric material. Such a design ensures the electrical separation of adjoining segments while permitting the breakdown voltage between adjacent exposed surfaces to be minimized.

Abstract: An angular rate sensor system is disclosed, consisting of a balanced resonant sensor. The sensor consists of a tuning fork of a piezoelectric material, preferably of quartz. The tines of the tuning fork are caused to vibrate electromechanically, for example, by impressing an alternating voltage on a pair of electrodes on each tine. This will cause the tines to vibrate. Any component of angular motion around the axis of the sensor causes a cyclic deflection of the tines at right angles to the normal driven vibration of the tines. If the rotational input to the handle of the sensor is applied through a torsion element, the resulting tine deflection is directed to cyclically rotate the entire sensor along the input/output axis. This deflection can be used for changing the capacitance of a capacitance bridge, or for generating an electric signal, due to the piezoelectric effect resulting from the deflection. Finally, the output signal may consist of a frequency-modulated signal or an optical pick-up may be used.

Abstract: The antenna of the invention is suitable for use with an aircraft and is capable of receiving a plurality of frequency ranges in the communication band and provides a directional antenna. To this end there is provided an upper wing element from which extend vertically two outer leg elements and a central leg element. The central leg element extends into a fairing disposed below and substantially coextensive with the wing element. Two symmetrical slots are disposed in the wing element symmetrically disposed about the central axis. Another slot extends through the central leg element and the fairing. The slots are provided with capacitors to provide antiresonant circuits at predetermined frequency ranges.