Flight instruments found in the cockpit of any aircraft are worth their weight in gold since they provide vital information concerning the flight status of the craft. Real-time data concerning altitude, airspeed and direction, for example, are readily available so pilots can safely navigate, especially, in accordance with the US Code of Federal Regulations.
Regardless of whether a plane is 10 years old or a tech-advanced version, traditional instruments are utilized as a back-up system if the main system becomes unreliable. Three types of basic flight instruments, exist: 1) pitot-static 2) compass systems and 2) gyroscopic instruments.
Let’s delve a bit deeper into what these three, basic flight systems, provide.
*** The Altimeter: the altimeter displays the aircraft’s altitude above sea-level using what are called aneroid capsules. These capsules expand, or contract, depending on whether the aircraft is in ascent or descent, causing the altimeter to indicate whether the plane’s position is in a higher or lower altitude.
*** The Airspeed Indicator: the airspeed indicator reveals the plane’s speed, typically as ‘knots’, as it relates to the surrounding air. The color-coded panel tells the pilot if the craft is in stall speed, never-exceed speed, or safe flap operation speeds.
*** The Vertical Speed Indicator: the vertical speed indicator is synonymous with ‘variometer’; and it has the ability to determine changing air-pressure. Air-pressure information is relayed to the pilot as a rate-of-climb or descent in feet-per-minute, meters-per-second or knots.
*** The Magnetic Compass: as it relates to magnetic north, it is the magnetic compass that indicates the aircraft’s heading. The compass system, though dependable during level flights, can provide readings that can be misleading when turns, climbs, descents or accelerations take place due to the downward slope of the Earth’s magnetic field. Because of this, a ‘heading indicator’ is utilized which is unaffected by dip and acceleration errors.
*** The Attitude Indicator: the attitude indicator, also known as ‘artificial horizon’, reveals the aircraft’s positioning, relative to the horizon of the earth – this would include the levelness of the wings and if the nose of the plane is pointing above or below the horizon. Also, during poor-visibility conditions, the attitude indicator is extremely helpful. At times, weather conditions such as over-clouding or storms will dictate that pilots must fly, mostly, by reference to instruments rather than by outside visual clues. Without external visuals, the internal source of attitude information is provided by the attitude indicator, providing the ‘artificial horizon’.
*** The Heading Indicator: the heading indicator, or directional gyro, reveals the craft’s heading as it applies to magnetic north, when set with a compass. More-sophisticated aircraft, however, utilize a ‘horizontal situation indicator’, instead of a heading indicator which, also, provides navigation data.
*** The Turn Indicator: the turn indicator incorporates the Turn-and-Slip Indicator as well as the Turn Coordinator which reveal rotation about the longitudinal axis. An inclinometer reveals if the aircraft is in coordinated flight, meaning the aircraft is in flight without sideslip, or moving slightly sideways and forward relative to oncoming airflow. When zero sideslip exists, the instrument panel will display a ball in the center of the spirit level.
The dizzying array of dials, switches, lights and sounds of the cockpit’s instrument panel is the pilot’s lifeline to flight safety as well as a vital connection to airfields and air-traffic controllers, below. Yes, the flight systems embedded in a cockpit’s instrument panel ARE worth their weight in gold!