Safe, economical, and reliable operation of modern airplanes is dependent upon the use of instruments. Instrumentation is basically the science of measurement. Speed, distance, altitude, attitude, direction, temperature, pressure, and engine revolutions are measured and these measurements are displayed on instrument dials in the airplane's cockpit. There are those which are referred to as "flight instruments" and others are termed "engine instruments." Only the basic instruments found in typical general aviation airplanes are discussed here (Fig. 2-19).
