The attitude indicator (also known as an artificial horizon) shows the aircraft's attitude relative to the horizon. From this the pilot can tell whether the wings are level and if the aircraft nose is pointing above or below the horizon. This is a primary instrument for instrument flight and is also useful in conditions of poor visibility. Pilots are trained to use other instruments in combination should this instrument or its power fail.
The airspeed indicator shows the aircraft's speed (usually in knots ) relative to the surrounding air. It works by measuring the ram-air pressure in the aircraft's pitot tube. The indicated airspeed must be corrected for air density (which varies with altitude, temperature and humidity) in order to obtain the true airspeed, and for wind conditions in order to obtain the speed over the ground.
Attitude Indicator
Shows the aricrafts attitude relative to the horizon. The outer ring shows increasing bank angles of 10, 20, 30, 60 and 90 degrees, while the two white diagonal lines show bank angles of 15 and 45 degrees. The central scale indicates nose pitch above and below the horizon in 5 degree increments.
Heading Indicator
This instrument is a directional gyro and shows you the direction you are heading. The outer ring numbers are at 30 degree intervals with 5 and 10 degree increments between. When talking about headings it is important to understand their meaning. The image shows that we have a heding on the dial of