Cockpit Basics

Cockpit Basics  
 
A general tour of the instruments, buttons, and levers in your airplane
Airplanes have evolved from relatively simple to incredibly complex machines. But remember: Whether you're flying a Cessna Skyhawk SP Model 172 or a Boeing 777–300, you're still flying an airplane, and airplanes are more alike than not. In the cockpit, for instance, most modern airplanes share six basic cockpit instruments: airspeed indicator, altimeter, attitude indicator, heading indicator (directional gyro), turn coordinator, and vertical speed indicator. Learning to use these six instruments and a few common controls, such as trim and flaps, will put you far down the runway toward flying any aircraft you wish.
Pitot Static Instruments
Three of the six primary flight instruments measure air pressure. These instruments—the altimeter, airspeed indicator, and vertical speed indicator—are called the pitot static instruments.
All three pitot static instruments are connected to a static port called the pitot tube. This port, or intake, introduces outside air into the case of each instrument. As an airplane climbs or descends, air pressure decreases or increases. The altimeter and vertical speed indicator display these pressure changes as altitude and rate of climb or descent.
The airspeed indicator, which is also connected to the pitot tube, measures the difference between static pressure and ram air pressure. Ram air pressure is the air pressure created when outside air enters the pitot tube. As the airplane flies faster, outside air is forced into the pitot tube more rapidly, increasing the ram air pressure. The airspeed indicator displays the pressure difference between static pressure and ram pressure as airspeed, usually in knots or Mach number.
Gyroscopic Instruments
Three of the six primary flight instruments use gyroscopes to provide pilots with critical flight information about the airplane's attitude, heading, and rate of turn.
Rigidity in Space and Precession
Gyroscopes work like spinning tops. They have two properties—rigidity in space and precession—that make them useful in flight instruments. See sidebar: Gyroscopic Properties.
The attitude indicator and heading indicator are based on a gyro's rigidity in space. Because a gyro resists being tipped over, it can provide a stable reference to the real horizon or to a specific direction.
The turn coordinator uses precession to display information about the direction and rate of turn. (For more information on precession, see the Gyroscopic Properties sidebar.)
Gyro Power