L-1011 ECS: Normal Rate Selector (21-21)

The normal rate selector controls the cabin altitude rate of change when the mode selector is in the NORM position. When set a the DOT, the cabin rate of change is approximately 500 feet per minute up and 300 feet per minute down. The desired rate of cabin change can be changed by selecting different positions with the rate knob. Here are the pressurization rate limitations:

Ascent

• Minimum 50 to 400 FPM
• Dot Indexed 400 to 850 FPM
• Maximum 1250 to 2400 FPM 

Descent 

• Minimum 50 to 350 FPM
• Dot Indexed 150 to 550 FPM
• Maximum 750 to 1450 FPM