Aviation Navigation and Time Conversions

The two ends of the Earth's rotation axis. They are not aligned with the magnetic poles, and their positions shift slightly within the Earth each year.

The direction a freely suspended magnet aligns with due to Earth's magnetic field. It is also known as the magnetic meridian.

The direction measured from Magnetic North clockwise through 360 degrees, denoted by the letter (M).

The angle between True North and Magnetic North. It is expressed in degrees East or West from True North.

The direction the aircraft's longitudinal axis (the line running from the nose to the tail) points. It's the direction the plane is facing.

If Magnetic North is the same as True North, there is no variation. However, when Magnetic North is to the West of True North, the variation is considered Westerly. This means the Magnetic North reading will be to the West of True North.

If Magnetic North is the same as True North, there is no variation. However, when Magnetic North is to the East of True North, the variation is considered Easterly. This means the Magnetic North reading will be to the East of True North.

The difference between True North (the geographic North Pole) and Magnetic North, which is where the compass needle points.

The difference between magnetic north and compass north caused by magnetic materials in an aircraft.

When the compass reading is east of the actual magnetic north, meaning the deviation angle is positive.

When the compass reading is west of the actual magnetic north, meaning the deviation angle is negative.

Lines on aeronautical charts that connect places with the same magnetic variation.

Lines on aeronautical charts that connect places with no magnetic variation.

Variation is east of true north, meaning you need to adjust westward to find true north.

Variation is west of true north, meaning you need to adjust eastward to find true north.

The angular distance on the Earth's surface measured from the Greenwich meridian to the location of a particular time zone. It can either be East or West of the Greenwich meridian and its measurement is in degrees, minutes, and seconds.

The time at the Greenwich meridian, which is the standard reference time for all other time zones.

The process of converting local mean time (LMT) to UTC by adding or subtracting the longitude of the time zone, depending on whether it's east or west of Greenwich.

The time at the Greenwich meridian, but calculated based on the Earth's rotation relative to the stars, making it more accurate than GMT.

The time at any specific location on Earth, determined by its longitude and the Earth's rotation.

A line on the Earth's surface that runs from North to South, marking a specific longitude and separating different time zones.

The time it takes for the Earth to complete one full rotation on its axis.

The angular distance on the Earth's surface measured from the equator to a specific location, expressed in degrees, minutes, and seconds. It can be either North or South of the equator.

The rule that states the further east a location lies, the less advanced its Coordinated Universal Time (UTC) is, and the further west a location lies, the more advanced its UTC is.

The time that pertains to the 0° meridian in Greenwich, England. Also known as Greenwich Mean Time (GMT).

A standard time that is adopted by a country or region to simplify timekeeping.

The 180° meridian that marks the dividing line between dates on Earth. When crossing it on a westerly track, a day is added to the calendar, and when crossing it on an easterly track, a day is subtracted.

Crossing the International Date Line from east to west results in a day being subtracted from the calendar.

Crossing the International Date Line from west to east results in a day being added to the calendar.

The angle between the Earth's magnetic field lines and the horizontal plane at a specific location.

Lines on a map connecting locations with the same angle of dip.

The line on the Earth's surface where the angle of dip is zero. It's close to, but not the same as, the geographic equator.

The total magnetic force exerted by the Earth at a specific point.

The deviation caused by permanent magnetism in the aircraft, like that of hard iron.

The deviation caused by induced (temporary) magnetism in the aircraft, like that of soft iron.

The three parameters (P, Q, R) representing the components of hard iron magnetism in an aircraft.

A material, like steel with cobalt or chromium, that retains its magnetism even after the magnetizing field is removed.

A material, like soft iron, that easily becomes magnetized when exposed to a magnetic field, but loses its magnetism quickly when the field is removed.

The Earth acts like a giant magnet with a magnetic field extending around it. This magnetic field is responsible for the compass needle pointing towards the North.

The difference between Magnetic North, where a compass needle points, and True North, the actual geographic location of the North Pole.

An imaginary line connecting the Earth's magnetic North and South poles. It's the direction a compass needle aligns with.

The angle at which a compass needle dips towards the Earth's surface. This angle varies depending on your location.