The Six Pack Explained
The instruments in the six pack are powered by various aircraft systems. The Airspeed Indicator, Altimeter, and Vertical Speed Indicator use the pitot-static system, which provides ram air pressure from the pitot tube and ambient pressure from the static port. Only the Airspeed Indicator uses the pitot tube; all three instruments use the static port.
The Attitude Indicator, Heading Indicator, and Turn Coordinator are gyroscopic instruments that contain an internal gyro powered by vacuum, pressure, or electrical power.