Definition
The group of cockpit flight instruments that derive their indications from air pressure sensed by the aircraft's pitot tube and static ports. The three primary pitot-static instruments are the airspeed indicator, the altimeter, and the vertical speed indicator.
Plain English
These are the cockpit gauges that work by measuring outside air pressure. They tell the pilot how fast the aircraft is going, how high it is, and whether it is climbing or descending.
Context Anchor
Seen in cockpit instrument discussions, preflight checks, and training on the airspeed indicator, altimeter, and vertical speed indicator.
Derivation
Pitot comes from Henri Pitot, an 18th-century French engineer who designed a tube to measure the speed of moving water; the same principle was later applied to air. Static simply means 'still' or 'unmoving' -- the static ports sample the still, undisturbed air around the aircraft. So pitot-static instruments use a combination of moving air pressure (from the pitot tube) and still air pressure (from the static ports) to do their job.
Why Pilots Care
They supply the primary flight data for airspeed and altitude; blockages or icing can produce incorrect readings that lead to loss of control.
Grounding Statement
As the airplane moves forward and changes height, these instruments turn changing air pressure into useful cockpit readings.
Intuition Check
Static does not mean electrical static here. It means outside air pressure sensed from relatively undisturbed air around the aircraft.
Example Sentence 1
During the preflight, the pilot checked the pitot tube and static ports because the pitot-static flight instruments depend on those openings being clear.
Example Sentence 2
After clearing ice from the pitot tube, the pitot-static flight instruments returned to normal indications on the next flight.