Adaptive Eductor System

An eductor for a gas turbine engine comprising:

• a first zone having a first fluid flow at a first pressure;
• a second zone having a second fluid flow at a second pressure;
• a lubrication sump cavity in fluid communication with said first zone and a sump vent;
• and
• an eductor valve system having a fluid flow path therethrough in fluid communication with said second zone and said sump vent, and comprising an altitude sensing valve in parallel through said fluid flow path with a gage pressure sensing valve.

An apparatus comprising:

• a gas turbine engine having a low pressure compressor zone and a high pressure compressor zone;
• said low pressure compressor zone having a fluid flow at a first pressure corresponding to a power output of said engine;
• said high pressure compressor zone having a fluid flow at a second pressure corresponding to said power output of said engine;
• a lubrication sump cavity in fluid communication with said low pressure compressor zone and a sump cavity vent;
• and
• an eductor valve system having a fluid flow path therethrough in fluid communication with said high pressure compressor zone and said sump vent, and comprising an altitude sensing valve, a first gage pressure sensing valve, and a second gage pressure sensing valve;
• wherein said altitude sensing valve is in parallel through said fluid flow path with said first gage pressure sensing valve;
• and
• wherein said altitude sensing valve is in series through said fluid flow path with said second gage pressure sensing valve.