Navigation Flashcards
Define Conformal
All angles and bearings on the Earth are accurately represented
Define Graticule
Mesh of parallels of latitude and meridians
Define Meridian
Semi-great circle joining North and South geographic poles
Define Parallels of latitude
Small circle on Earth’s surface such that the plane lies parallel to the plane of the equator
Define Rhumb Line
Lines on the Earth’s surface which cross all meridians at same angle such that true direction remains unchanged
Define Small Circle
Any circle drawn on Earth’s surface such that the plane does not pass through the Earth’s centre.
Define Great Circle
Any circle drawn on the Earth’s surface such that the plane of the circle passes through the Earth’s centre.
Define Chart
Projection on which additional information is provided relating to a particular need.
Define Map
Representations of Earth’s surface overlaid with specific info, typically essential geographical and topographical features
Define Equator
Great circle drawn on Earth’s surface which lies midway between the geographic poles, perpendicular to the axis of rotation. Forms the datus against which all other parallels of latitude are numbered.
What should be taken account of when using maps?
Use of True North Issue date Typre of projection Scale Suitability of accuracy
What information could be on a map?
Lattitude Longitude Topography Geographic data Landmass outlines Relief Divisions of Airspace Danger areas
What is the effect of compression?
Polar diameter is 27 stature miles shorter than equatorial diameter
Define Air Speed
The speed at which an aircraft moves through the air mass it is flying through.
How is indicated air speed measured?
Pitot tube in the direction of airflow senses total pressure.
Static pressure value is removed in static vent, leaving only the dynamic pressure
What is static pressure?
The pressure exerted equally in all directions at any point in the atmosphere.
What is dynamic pressure?
Pressure in relation to movement
What is a nautical mile?
Length of an arc of a great circle subtended by one minute of the angle from the Earth’s centre
In feet, what is the length of nm, sm and km?
nm - 6078ft/6080ftuk
sm - 5280ft
km - 3280ft
What errors might indicated air speed (IAS) have?
Instrument: Faults in the construction of the indicator.
Position: Caused by poor siting of the Pitot tube.
Density: temperature will change air density affecting pressure.
Compressibility: at excess of 300kts the air ahead of the aircraft becomes compressed.
What is Rectified Air Speed (RAS)?
IAS corrected for instrument and position error.
What is True Air Speed (TAS)?
RAS corrected for density and compressibility error.
What is groundspeed?
TAS corrected for wind.
The speed at which an aircraft travels over the ground.
Triangle of Velocities
Air velocity > Air position
Ground velocity»_space; ground position
Wind velocity»_space;>
Three map formats?
Mercator projection
Transverse Mercator
Lambert’s Conic Projection
