General

When considering the pitot static system it is important to be aware of and understand three different pressure types. 

• Static pressure, which is the ambient pressure surrounding you when standing still
• Dynamic pressure, which is the pressure created as a result of an object in motion and;
• The Total Pressure (stagnation pressure) which is the sum of dynamic and static pressure.

The pitot static system consists of two primary pressure sensing elements: the pitot tube and static port. The pitot tube has a small opening at the front that measures the total pressure. In addition to the larger hole in the front of the pitot tube, there is a small hole in the back of the chamber that allows moisture to drain from the system should the aircraft enter precipitation.  The pitot tube is also typically heated to prevent ice buildup.

Static ports are small holes exposed to the free undisturbed air on the side(s) of the aircraft.  They measure the static (ambient) pressure. An alternate static source is provided in some aircraft to provide static pressure indications should the primary static source become blocked.