Definition
The group of flight instruments that operate by sensing and comparing air pressures captured by the aircraft's pitot tube and static ports. This group includes the airspeed indicator, altimeter, and vertical speed indicator. The pitot tube measures ram (impact) air pressure from the aircraft's forward motion, while the static ports measure the ambient (still) air pressure of the surrounding atmosphere. Each instrument uses one or both of these pressure sources to display a different aspect of the aircraft's motion through the air.
Plain English
A set of three cockpit instruments — airspeed indicator, altimeter, and vertical speed indicator — that work by measuring outside air pressure. They use a forward-facing tube and small flush holes on the side of the aircraft to sense pressure changes as the aircraft moves and climbs or descends.
Context Anchor
Seen in instrument flying, preflight checks, cockpit instrument scans, and discussions of pitot tube or static port blockage.
Derivation
Pitot is named after Henri Pitot, an 18th-century French engineer who invented a tube to measure the speed of flowing water. Static comes from the Latin staticus, meaning 'standing still' — referring to the undisturbed ambient air pressure around the aircraft. Together the name describes exactly how the instruments work: one source captures moving (ram) air, the other captures still air.
Why Pilots Care
These instruments provide the primary airspeed, altitude, and climb/descent information required for safe flight, especially when visual references are unavailable.
Analogy
Think of the system like using two pressure clues at once: one clue from air being pushed into a tube, and one clue from the outside air around the airplane. The instruments compare those clues and turn them into useful cockpit readings.
Intuition Check
“Static” does not mean the instrument is inactive or unchanging here. It means the system uses outside air pressure that is not being forced into the airplane by forward motion.
Example Sentence 1
During preflight, the pilot checked that the pitot tube cover was removed and the static ports were clear, since all the pitot/static instruments depend on those openings.
Example Sentence 2
When the pitot tube iced over, the pilot noticed the airspeed indicator became unreliable while the other pitot-static instruments continued to work.