Abstract: The pitches of the several blades in a helicopter rotor assembly are controlled by individual blade control subsystems. Those blade control subsystems respond to the output signals from accelerometers mounted on the blades. The signals from the accelerometers are used to control the pitch of the blades on which the accelerometers are mounted as well as the pitch of other blades. By appropriate orientation of any accelerometer and filtering within a particular feedback subsystem, each subsystem is designed to correct particular modes of blade motion to the exclusion of other modes of motion by varying lift.

Abstract: Fast alkali-metal-ion transporters are provided having low resistivities and low-activation-energy mobilities at temperatures at which alkali metals are molten. The novel compounds promote alkali-metal-ion transport in three dimensions within their crystalline structure and have the general formula:A.sub.n X.sub.2 (ZO.sub.4).sub.3orA.sub.m (Z'.sub.2 O.sub.4)wherein A is potassium, sodium or lithium, Z' is a tetrahedrally coordinated cation or mixtures thereof, X is an octahedrally coordinated cation or mixtures thereof, n is a number greater than 1 and less than 4, m is a number from 1 up to 2 and Z' is a mixture of at least two Z' cations.