Patent ID: 7849702

Claim:
An environmental control system (ECS) for use with an aircraft, the ECS comprising: a ram air inlet door operably coupled to a ram air inlet proximate a fuselage of the aircraft; an air conditioning pack that receives a first portion of air from the ram air inlet; a heat exchanger that receives a second portion of air from the ram air inlet, wherein the first portion of air from the ram air inlet flows from the air conditioning pack and through the heat exchanger before flowing into a cabin of the aircraft, and wherein the second portion of air from the ram air inlet cools the first portion of air in the heat exchanger; a ram air outlet door operably coupled to a ram air outlet that exhausts the second portion of air away from the aircraft after the second portion of air passes through the heat exchanger; and means for automatically controlling the ram air inlet door and the ram air outlet door during operation of the ECS to control ram air flow, to increase air pressure recovery downstream from the ram air inlet door, and to reduce aerodynamic drag caused by the ECS, wherein the means for automatically controlling the ram air inlet door and the ram air outlet door include: means for automatically selecting a position of the ram air inlet door based on a ram air inlet mass flow requirement; and means for automatically selecting a position of the ram air outlet door based on the selected position of the ram air inlet door to thereby increase air pressure recovery downstream from the ram air inlet door and reduce aerodynamic drag.