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## Temperature

Basic Instruments

Determination of correct temperature is necessary for accurate computation of airspeed and altitude. Temperature, airspeed, and altitude are all closely interrelated, and the navigator must be familiar with each in order to work effectively and accurately. Temperature Gauges The temperature gauge that is most commonly used in aircraft employs a bimetallic element. The instrument is […]

## Absolute Altimeter

Basic Instruments

Accurate absolute altitude is an important requisite for navigation, as well as for safe aviating. It is particularly important in pressure pattern navigation. Absolute altitude may be computed from the PA readings if the position of the aircraft is known, but the results are often inaccurate. Under changing atmospheric conditions, corrections applied to PA readings […]

## Altimeter Errors

Basic Instruments

The pressure altimeter is subject to certain errors that fall in five general categories. Mechanical Error A mechanical error is caused by misalignment of gears and levers that transmit the aneroid cell expansion and contraction to the pointers of the altimeter. This error is not constant and must be checked before each flight by the […]

## Altitude and Altimeters

Basic Instruments

Altitude may be defined as a vertical distance above some point or plane used as a reference. Knowledge of the aircraft altitude is imperative for terrain clearance, aircraft separation, and a multitude of operational reasons. There are as many kinds of altitude as there are reference planes from which to measure them. Only six concern […]

## Compasses (Part Three)

Basic Instruments

Gyro-Magnetic Compass Indicators The gyro-magnetic compass indicators are remote-reading, movable dial compass indicators. They are intended for supplementary use as directional compass indicators when used with the compass system. The indicators duplicate the azimuth heading of the master indicator heading pointer. A setting knob is provided at the front of each indicator for rotating the […]

## Compasses (Part Two)

Basic Instruments

Deviation Because deviation depends upon the distribution of magnetic forces in the aircraft itself, it must be obtained individually for each magnetic compass on each aircraft. The process of determining deviation, known as compass swinging, should be discussed in the technical order for each compass. Deviation changes with heading are shown in Figure 3-6. The […]

## Compasses (Part One)

Basic Instruments

A compass may be defined as an instrument that indicates direction over the earth’s surface with reference to a known datum. Various types of compasses have been developed, each of which is distinguished by the particular datum used as the reference from which direction is measured. Two basic types of compasses are in current use: […]

## Direction

Basic Instruments

Basic Instruments The navigator must have a fundamental background in navigation to ensure accurate positioning of the aircraft. Dead reckoning (DR) procedures aided by basic instruments give the navigator the tools to solve the three basic problems of navigation: position of the aircraft, direction to destination, and time of arrival. Using only a basic instrument, […]