Abstract: An improved thermal control system for flight apparel worn in an aircraft. An environmental control system (11) produces both a flow of cold air in a duct (12) and a flow of warm air in another duct (14). A mixing chamber (16) is connected to both ducts (12, 14) and mixes the flows of cold and warm air received therefrom to produce a flow of personal conditioning air. A valve (32), positioned in the warm air duct (14), controls the amount of warm air flowing into the chamber (16). The valve (32) is operated to adjust the mixing of warm air with cold air in the chamber (16), to thereby adjust the temperature of the personal conditioning air so that it is at a temperature which is comfortable. A comfortable temperature is selected by a control switch (28). The valve (32) is continuously adjusted in accordance with temperature signals received from a temperature sensor (30). A controller minimizes the error between the temperature served by the sensor (30) and the temperature selected by the control switch (28).

Abstract: A breathing system (10) is provided for supplying physiologically acceptable breathing gas (oxygen partial pressure greater than that required to prevent hypoxia) to a pilot of an aircraft. The system (10) includes a breathing mask (12) connected to a pressure regulator (14). The pressure regulator (14) is connected to a selector valve (32). Connected to the selector valve (32) is an onboard oxygen generating system (22) and a standby oxygen supply (24). The selector valve (32) selects breathing gas from one of these two sources. Also included in the system is an emergency oxygen bottle (26) connected to the regulator (14). Ambient air is supplied to the mask (12) by an ambient airflow duct (20) if for some reason none of the breathing gas sources (22, 24, 26) provide breathing gas to the regulator (14).

Abstract: A drain structure for facilitating the draining of liquid condensate from inside an aircraft whenever air pressures inside and outside the aircraft are substantially equal. A pressure-sensitive apparatus is provided in conjunction with a drain opening through the aircraft's outer skin so that liquid can pass through the drain opening only while the apparatus is open. The apparatus includes a housing and a valve in the form of a slider movable within the housing to open and close the apparatus in response to the pressure differential between the inside and the outside of the aircraft. The housing defines a liquid passageway between the inside of the aircraft and the drain opening, and the slider closes the apparatus by blocking this liquid passageway whenever there is a substantial pressure differential between the inside and the outside of the aircraft.

Abstract: Hot compressed air is bled from the compressor of an engine and a portion of it is directed through a flow through type indirect heat exchanger of ring form located within an annular chamber in the engine cowl which is partially formed by lip surfaces of the inlet. Such air gives up heat to low pressure air within such chamber which carries the heat to the inlet surfaces. The compressed air is then removed from the heat exchanger and is admixed with additional hot compressed air. A part of the mixture is delivered to a wing TAI subsystem and a second portion is used for cabin conditioning and pressurization.

Abstract: A thermostat for a pneumatic control system controls output pressures to a plurality of elements to be controlled. The thermostat can control output pressure directly or inversely and linearly or nonlinearly with respect to temperature. Additionally, the pressures can be controlled sequentially or simultaneously.

Abstract: In an air conditioning system for an aircraft cabin, stale air is withdrawn from the cabin, then filtered, compressed and cooled in a recirculation loop which returns the reconditioned air to an air distribution manifold that supplies the cabin with fresh air. The compression stage moves the air through the recirculation loop and is provided by an air compressor driven by a power turbine that is in turn rotated by a flow of cabin air to an overboard exhaust nozzle caused by a cabin-to-ambient pressure differential. Cooling is provided by an air/air heat exchanger that transfers heat from the recirculation air, warmed by the compression stage, to cooler air discharged from the output side of the power turbine and flowing to the overboard exhaust nozzle. In one embodiment, the foregoing recirculation loop is integrated with an air cycle machine refrigeration stage of a conventional cabin air conditioning system supplied by fresh engine bleed air.

Abstract: Apparatus for monitoring the operational status of the air delivery and momentum injection subsystems of a Boundary Layer Control (BLC) system of an aircraft, by sensing an air flow parameter in the supply duct supplying air to the BLC manifold is disclosed. The air flow parameter is sensed as a ratio of two discreet pressures [stagnation/static (P.sub.T /P.sub.S) or static/static (P.sub.S1 /P.sub.S2)]. When the ratio falls outside of a predetermined range, an indication that the air delivery and momentum injection subsystem has failed is provided. The failure may be due to either a rupture or a blockage of the air delivery and momentum injection subsystem. A combined BLC status indication is provided by combining the signal related to the sensed air flow parameter with signals related to the correctness of the position of the valves controlling the bleed air flowing to the air delivery momentum and injection subsystem and the position of the high lift surfaces (e.g., flaps) of the aircraft.