Navigation404-01

Ground School 2014

CI Pesto

Navigation: The process or activity of accurately ascertaining one’s position and planning and following a route

• Why is Navigation important from an Aviation perspective?

Discussion topics in this lesson

Latitude and Longitude-Meridians and Parallels-Geographical Coordinates-Time and Longitude-Coordinated Universal Time-Great Circles and Rhumb Lines

Heading-True and Magnetic

Bearing

Speeds-True airspeed, Indicated airspeed and Ground speed

Meridians of Longitude

• Semi great circles joining the true or geographic poles of the earth (true meridians).

• They are measured from 0 to 180 degrees East and West of the PRIME MERIDIAN, which runs through Greenwich, England.

• The meridian opposite the prime meridian (180) is called the INTERNATIONAL DATE LINE and here time changes a day.

• Meridians are measured in degrees, minutes and seconds.

There are 60 minutes in a degree and 60 seconds in a minute.

RUN: North-SouthMEASURE: East-West

Parallels of Latitude

• Circles on the earth's surface whose planes lie parallel to the equator. The lines never touch

• Equator is a great circle on the surface of the earth lying equidistant from the poles.

• Latitude is measured from 0 to 90 degrees North and South of the EQUATOR , which is numbered 0 degrees.

• Parallels of Latitude are also expressed in degrees, minutes and seconds.

RUN: East-WestMEASURE: North-South

Geographical Coordinates

• Intersection of the lines of latitude and longitude marking a position on a map.

• Used to locate a fixed object on the earth's surface.

• Change of latitude and the change of longitude between two places relate one position on the surface with another.

Time and Longitude

• Interval between two successive transits of the sun. It is divided into 24 hours.

• The sun travels once around the earth, which is 360 degrees of longitude, in one day.

• So, time can be expressed in terms of longitude.

Coordinated Universal Time

• Used so that a universal standard time exists for reference at any point on the earth.

• Based upon measurements of time in a number of places on the earth.

• It is also referred to as Z or zulu time.

• UTC replaced Greenwich mean time (GMT), which was once the universally accepted standard.

• UTC is the local mean time for the prime meridian.

Great Circles and Rhumb Lines

• GREAT CIRCLE

• A circle on the surface of the earth whose plane passes through the center of the earth. It is also the shortest distance between two points on the surface of the earth.

• RHUMB LINE

• A curved line on the surface of the earth cutting all meridians at the same angle. All parallels of latitude are rhumb lines.

Heading

• The direction that the aircraft nose (longitudinal axis) is pointing, measured clockwise from north.

True and Magnetic Heading

• TRUE HEADING

• Is measured from true north.

• MAGNETIC HEADING

• Is measured from magnetic north.

Bearing

• The position of an object relative to your aircraft.

• This angle is also known as the azimuth.

• Measured clockwise from the meridian through 360 degrees.

• Has nothing to do with the aircraft heading.

Speeds

• SPEED

• The rate at which an object moves in relation to a fixed object.

• MPH (Miles per Hour)

• Speed in statute miles per hour.

• KNOTS

• Speed in nautical miles per hour.

• KPH (Kilometers per hour)

• Speed in kilometers per hour.

True, Indicated and Ground Airspeed

• TRUE AIRSPEED

• Speed of the aircraft relative to the air.

• INDICATED AIRSPEED

• Speed shown on the airspeed indicator.

• GROUNDSPEED

• Speed of the aircraft relative to the ground.

Reading and Questions:Please read pages 175-177

There will be a quiz next class

Have a Great Week!