Lesson 16: Aircraft Instrument Systems Classification Of Instruments Flight Instruments Engine Instruments
Auxiliary Instruments Flight Instruments Those that help visualize the attitude, location and speeds of the aircraft. Those which indicate the relationship to the air
through which we are flying Those which relate to our position in space without considering the air. Pitot-static System Dynamic Air Pressure - Pressure caused by moving
air. Ambient Static Air Pressure - Pressure of nonmoving air just outside the aircraft. Pitot-static System Pitot Head
Pitot Head Flush Static Port Airspeed Indicator
Differential pressure gauge that measures the difference between
dynamic and ambient static air pressure. Airspeed Indicator
Indicated airspeed The speed of an aircraft as shown on the airspeed indicator.
True airspeed The speed at which an aircraft is moving relative to the surrounding air.
Calibrated airspeed Indicated airspeed of an aircraft, corrected for installation and instrument errors. Altimeter
A barometer that measures the absolute pressure of the air. Altimeter
Indicated Altitude The altitude shown by an altimeter set to current altimeter setting. Pressure Altitude Height above the standard pressure level of 29.92 in.Hg.
Density Altitude Pressure altitude corrected for nonstandard temperature variations. Altimeter True Altitude
The actual height of an abject above mean sea level. Absolute Altitude Actual height above the surface of the earth, either land or water.
Vertical Speed Indicator The rate of climb indicator
Serves only as a backup for the altimeter and airspeed
indicator as a pitch indicating instrument.
Helps the pilot establish a rate of climb or descent. Blockage Of The Pitot-Static System
Pitot Tube Affects only the airspeed indicator, but a clogged static system affects all three pitotstatic instruments. If the pitot tube is blocked and its drain hole remains open, the airspeed reading will drop to zero.
If both pitot tube and the drain hole clog, the airspeed indicator will react like an altimeter. Blockage Of The Pitot-Static System Static port The indicated airspeed increases as the
airplane descends and decreases when it climbs. The altimeter: air pressure in the system will not change and neither will your indicated altitude. VSI continually indicates Zero.
Gyroscopic Instruments Gyroscopic Instruments Turn coordinator Attitude indicator
Heading indicator Gyroscopic Instruments Rigidity In Space Once a gyroscope is spinning, it tends to remain in a fixed position in space and resist external forces applied to it.
Gyroscopic Instruments Precession The tilting or turning of a gyro in response to pressure.
The reaction to this force occurs in the direction of rotation, approximately 90 ahead of the point where the force was
applied. Sources Of Power Gyroscopes may be operated by electrical power or by a vacuum (suction) system.
Sources Of Power Attitude Indicator Vacuum powered instrument which senses pitching and rolling movements about the airplanes lateral and longitudinal axes.
Attitude Indicator Attitude Indicator Directional Gyro
Vacuum powered instrument which senses yaw movement of the airplane about the vertical axis.
Horizontal card directional gyro Directional Gyro Vertical card
directional gyro Rate Gyros Turn And Slip Indicator Turn Coordinator
Inclinometer Rate Gyros Turn Coordinator
Floating Magnet-type Magnetic Compass Engine Instruments Engine Instruments
