Introduction

Aircraft became a practical means of transportation when
accurate flight instruments freed the pilot from the necessity
of maintaining visual contact with the ground. Flight
instruments are crucial to conducting safe flight operations
and it is important that the pilot have a basic understanding
of their operation. The basic flight instruments required
for the operation under visual flight rules (VFR) are airspeed
indicator (ASI), altimeter, and magnetic direction indicator.
In addition to these, operation under instrument flight rules
(IFR) requires a gyroscopic rate-of-turn indicator, slip-skid
indicator, sensitive altimeter adjustable for barometric
pressure, clock displaying hours, minutes, and seconds with
a sweep-second pointer of digital presentation, gyroscopic
pitch-and-bank indicator (artificial horizon), and gyroscopic
direction indictor (directional gyro of equivalent).