FLIGHT INSTRUMENTS

The pitot-static system is a source of pressure for operations of the following flight instruments:

1) Altimeter.

2) Vertical Speed Indicator.

3) Airspeed Indicator.

The Altimeter. The altimeter measures the height of the aircraft above a given level. Since it is the only instrument that gives altitude information, the altimeter is one of the important instruments in the aircraft. To use this altimeter effectively, the pilot must thoroughly understand its principle of operation and the effect of barometric pressure and the temperature on the altimeter.

Vertical Speed Indicator. The vertical speed indicator shows whether the aircraft is climbing, descending, or in level flight. The rate of climb or descent is indicated in feet per minute. If properly calibrated, this indicator registers zero in level flight.

The Airspeed Indicator. The airspeed indicator is a sensitive, differential-pressure gauge that measures and shows promptly the difference between (1) pitot, or impact, pressure, and (2) static pressure, the undisturbed atmospheric pressure at flight level.

The following flight instruments contain gyroscopes:

1) Turn and slip indicator.

2) Heading indicator (directional gyro).

3) Attitude indicator (artificial horizon or gyro-horizon).

Turn and Slip Indicator. Turn and slip indicator was one of the first modern instruments used for controlling an aircraft without visual reference to the ground or horizon. It is a combination of two instruments, a ball and a turn needle.

The Heading Indicator.The heading indicator(or directional gyro) is designed to facilitate the use of the magnetic compass.

The Attitude Indicator. The attitude indicator (or artificial horizon or gyro-horizon) with its miniature aircraft and horizon bar is the one instrument that gives a picture of the attitude of the real aircraft.