Compass

Definition

A compass is a navigational instrument that shows direction relative to the Earth's magnetic poles. It is essential for navigation, allowing pilots and sailors to determine their heading and maintain the desired course. The compass works by using a magnetic needle that aligns itself with the Earth's magnetic field, pointing towards magnetic north, which helps in establishing bearings and navigating accurately.

5 Must Know Facts For Your Next Test

1. A compass typically consists of a magnetized needle mounted on a pivot point, allowing it to rotate freely to align with the Earth's magnetic field.
2. The accuracy of a compass can be affected by nearby metallic objects or electronic equipment, which can distort the magnetic field.
3. Pilots use a compass along with other navigation tools, such as GPS and VOR systems, to ensure they stay on course during flight.
4. In aviation, understanding magnetic declination is crucial for accurately converting between magnetic heading and true heading.
5. Compasses can be classified into different types, including liquid-filled compasses and handheld compasses, each designed for specific navigational needs.

Review Questions

• How does a compass function in relation to the Earth's magnetic field?
  • A compass functions by utilizing a magnetized needle that aligns itself with the Earth's magnetic field. When the needle is allowed to move freely, it points towards magnetic north due to the Earth's natural magnetism. This alignment helps users determine their direction relative to the Earth's surface, which is crucial for navigation whether by air or sea.
• What are some factors that can affect the accuracy of a compass reading?
  • The accuracy of a compass reading can be affected by several factors including magnetic declination, which varies by location and must be accounted for. Additionally, nearby metallic objects or electronic equipment can create magnetic interference that distorts the compass reading. Pilots must also consider their altitude and surrounding geography, as these can influence how accurately they navigate using a compass.
• Evaluate the importance of understanding magnetic declination when using a compass for navigation.
  • Understanding magnetic declination is vital for accurate navigation because it represents the difference between magnetic north and true north. When navigators fail to account for this declination, they may end up off course, potentially leading to navigational errors. By adjusting for declination based on their geographic location, pilots ensure that their headings correspond accurately to their intended flight path, thereby enhancing safety and precision during navigation.

Related terms

magnetic declination: The angle between magnetic north and true north, which varies depending on geographic location.

gyrocompass: An advanced type of compass that uses a gyroscope to maintain orientation and provides true north regardless of the Earth's magnetic field.

heading: The direction in which an aircraft or vessel is pointed, expressed in degrees from magnetic north.