Abstract: An aircraft door drainage system includes a precipitation receptacle disposed longitudinally along an upper edge of an aircraft door opening. The receptacle is mounted along the upper edge of the door opening by a plurality of brackets that connect the receptacle to an inside ceiling panel of the aircraft. The receptacle protrudes outward from the upper edge of the door opening into a path followed by precipitation falling off of an outer peripheral surface of a fuselage of the aircraft from locations above, forward, and aft of the door opening into the door opening when the aircraft door is in an open position. The receptacle remains clear of the aircraft door when the aircraft door is closed into the door opening. Drain hoses are connected at first and second ends of the receptacle to direct precipitation collected in the receptacle to an outside of the aircraft.

Abstract: A gaseous medium containing aerosols is drawn through a quartz sampling tube and a filter located therein, with the aerosols becoming entrapped on the filter. The filter is located at the geometric center of a microwave cavity, and the principal resonance of the latter is tracked with the aid of an adaptive electronic circuit. The time rate of change of the resonant frequency is a function of the rate of deposition of particulate matter on the filter, and principally of the liquid water content of those aerosols. Water in the vapor phase passes through the filter and does not affect the measurement; solid particulate does affect the frequency shift but in a second order manner and is readily compensated for after measurement of total aerosol mass deposited and the determination of the dielectric constant of the solid species therein.

Abstract: An accelerometer comprising a first glass plate mounted in a fixed position, a second glass plate mounted in spaced relation with said first plate and movable with respect to said first plate, an aligning agent coating the facing surfaces of said plates, a nematic liquid crystal mixture filling the space between said plates, means applying an electrical potential between the coated surfaces of said plates, and means for detecting optical characteristics within said liquid crystal mixture.