Section One: 1. The Earth, 2. Aeronautical Charts Flashcards
What name is given to the point at which the Earth is closest to the Sun in its orbit?
Perihelion
What name is given to the point at which the Earth is furthest to the Sun in its orbit?
Aphelion
The Earth’s axial tilt means the sun’s position changes in what manner?
Latitudinally
In the Northern Hemisphere’s Summer solstice, where does the Sun appear directly overhead at noon?
Tropic of Cancer
In the Northern Hemisphere’s Winter solstice, where does the Sun appear directly overhead at noon?
Tropic of Capricorn
At the spring and autumn equinox, the Sun appears directly overhead where?
Equator
In reality, the Earth is what kind of shape?
A flattened spheroid
The Earth rotates around which axis?
Polar axis
For the purposes of practical navigation, the North Pole is the direction of…
True North
Basic reference for longitude
Greenwich Meridian
Greenwich Meridian is otherwise known as what?
Prime Meridian
The longitude of 180 degrees E/W is otherwise known as what?
Anti-meridian
Longitude is the angle between?
A location’s meridian of longitude and the Prime Meridian
The angle between a location’s meridian of longitude and the Prime Meridian is known as what?
Longitude
Slices of the Earth in longitude are given what term?
Meridian
Slices of the Earth in latitude are given what term?
Parallel
The North and South Poles are what degree of Latitude, respectively?
90 degrees
How is the degree of Latitude calculated?
Angle between the plane of the Equator and the line drawn to the parallel of Latitude at the Earth’s surface
What is a Great Circle?
A plane passing through the centre of the Earth when represented by a sphere
Meridians of longitude and the Equator can be described as what?
Great Circles
What are some navigational examples of Great Circles?
Meridians of Longitude and the Equator
The shortest distance between any two points on the Eath’s surface lie on what plane?
A Great Circle
Great Circles have two major properties:
Shortest distance between two points
There can only be one Great Circle (except between antipodal points)
Two locations that lie on exact opposite sides of the Earth are known as?
Antipodal points
Parallel of Latitudes can be described as what kinds of distances?
Small Circles
Example of Small Circles
Parallel of Latitudes
How is a specific plane through the Earth not a Small Circle?
It does not pass through the centre of the Earth
A spherical plane between two points that does not pass through the centre of the Earth is known as what?
Small Circle
What is the normal reference direction from which angles are measured?
True North
The distance between latitudes increases with what direction?
Heading towards the Equator (from either north or south)
What is the term given to the angle of inclination of two meridians at a latitude?
Convergence
Convergence = 0 where?
Equator
Why is there no longitudinal convergence at the Equator?
The meridians are parallel
Why is there full longitudinal convergence at the Poles?
The Poles are where the meridians ‘meet’
How is convergence calculated between two meridians at the poles?
The latitudinal angle between them at the Equator = convergence at the poles
What term is given to a line between two points that maintains a constant angle of direction relative to true north?
Rhumb line
3 instances when Great Circle line = Rhumb line
Flights along meridian of longitude
Flights along the Equator
Short distance flights
Why is the Great Circle of a flight along a meridian of longitude also its rhumb line?
All meridians are arcs of great circles
On a rhumb line flight, what will constantly change?
The track bearing
The Decimal Degree coordinate notation appends a negative ‘-‘ sign to which directions?
South and West
The Decimal Degree coordinate notation appends a negative ‘+’ sign to which directions?
North and East
1 nautical mile is equivalent to…
The angular distance of 1 minute of arc on the Earth’s surface
1 minute of latitude at any point on the Earth is equivalent to
1 nautical mile
Why does a nautical mile change in different locations?
The Earth is not a perfect sphere
How many feet in an international nm?
6076
How many metres in an international nm?
1852
1 degree of longitude is equal to what distance at the Equator?
60nm
1 degree of longitude is only equivalent to 60nm where?
Equator
What happens to the distance between degrees of longitude as you move further from the Equator?
The distance decreases (from 60nm)
What is the name given to a line that crosses all meridians of longitude at the same angle?
Rhumb line
A chart that preserves the angular relationships of the Earth’s features is described as what?
Conformal
What term is given to a map that views the Earth from ‘above’ (i.e. looking down from the North Pole)
Conic projection
Why does significant scale distortion occur with Standard Mercator Projection maps at higher latitudes?
Meridians converge at a greater angle so the map distorts
Highly detailed charts (such as the UK’s 1:250 000 aero-chart) use what version of map projection?
Transverse Mercator Projection
The Transerve Mercator Projection ‘wraps’ a cylinder at what relation to the Earth
The cylinder is wrapped so its sides are parallel to the plane of the Equator
Airspace information on UK 1:500 000 charts are given up to what level?
FL195
Airspace information on UK 1:250 000 charts are given up to what level?
FL50
An ATZ is only active when?
During the notified hours of operation of the ASTU (or A/G)
Free-fall parachuting can take place up to what level?
FL150
The large blue numbers in each quadrant of a chart are given what term?
Maximum Elevation Figures
MEFs appear on a chart at what interval?
Half a degree
Is the MEF a safety altitude?
No
Generally, a safety altitude is calculated using what?
MEF + 1000ft
Lines of equal magnetic variation are known as what?
Isogonals
An aerodome symbol with a larger circle and a ‘t’ by it denote what?
Training aerodrome
An aerodome symbol with a larger circle and a ‘u’ by it denote what?
An aerodrome with unusual activity
Aerodrome symbols given in purple instead of the normal blue denotes what?
Government-operated
A symbol of a circle with an ‘M’ in the middle denotes what?
Microlight flying site
Elevations of aerodromes on charts are given in what measurement?
Feet above Mean Sea Level
A gliding site with just a G and no altitude markings means what?
Gliding takes place without launch cables
A blue circular symbol with a bat-like symbol in the middle denotes what?
Hang/para gliding
In airspace markings on charts, broad banding denotes what?
Boundary of controlled airspace
In airspace markings on charts, narrow banding denotes what?
Level changes within the boundary
A ‘+’ symbol on airspace markings means the airspace’s upper vertical limit is..?
FL195
An area of a TMZ is marked by what?
Line of magenta semicircles
An area of a RMZ is marked by what?
Line of blue semicircles
An area of a RMZ/TMZ is marked by what?
Line of alternate blue and magenta semicircles
On a chart, a line of magenta semicircles indicates the boundary of a what?
TMZ
On a chart, a line of blue semicircles indicates the boundary of a what?
RMZ
On a chart, cables are indicated by what?
Zig-zag line
A flarestack’s flame could extend up to what?
600ft above the installation
Is a military aerodrome’s ATZ automatically part of a MATZ?
No
Important point to remember when transiting a MATZ?
You will require separate permission to enter the ATZ within the MATZ
On a chart, a VOR compass rose is orientated in what manner?
To magentic north
What does HIRTA stand for?
High Intensity Radio Transmission Area
What does GVS stand for?
Gas Venting Site
A cross-hatched area on a chart with bold boundary indicates a what?
Prohibited, Restricted or Danger Area
Prohibited, Restricted or Danger Area are indicated by what on a chart?
Cross-hatched area with bold boundary
A Prohibited, Restricted or Danger Area activated by NOTAM are shown with what?
Broken boundary lines
A broken boundary line on a Prohibited, Restricted or Danger Area means what?
The Area is activated by NOTAM
The strange ‘S’ symbol on a Danger area denotes what?
En-route Danger Area Information Service is available
Danger Area Information Service is known as what?
DAAIS
DAAIS stands for?
Danger Area Information Service
A red cross on a Danger Area description denotes what?
A Danger Area Crossing Service (DACS) is available
DACS stands for?
Danger Area Crossing Service
On a chart, red lines mark what?
Roads
On a chart, black lines mark what?
Railways
On a chart, yellow dots mark what?
Small villages
On a chart, ‘PS’ marks what?
Power station
Contours on the 1:500 000 chart occur at what interval?
500ft AMSL
A Lambert projection is best used for map presentation of what?
Mid-latitudes
Technical term for calculation involving distances at latitudes?
Departure
Departure calculation
Change in Longitude (Minutes) x Cosine of Latitude
Rhumb lines cross all meridians of longitude at…
The same angle
One Nautical Mile is defined as:
A change of latitude of one minute
A change of latitude of one minute is known as
A Nautical Mile
In cartography, what term defines the accuracy of directions on a map?
Conformity
In cartography, what term defines the accuracy of scale (distances) on a map?
Equivalence
A straight line on a Lambert map represents a
Great Circle
A map’s straight line represents a Great Circle constantly. What kind of map is this?
Lambert
Lambert pros/cons
Pro: conformity
Con: equivalence
A Lambert map’s equivalence is only accurate where?
Standard Parallels
What are standard parallels?
Where the Lambert map’s ‘cone’ touches the Earth’s surface and subsequently where equivalence is only accurate
Direct Mercator pros/cons
Pro:
Con: Conformity and Equivalence
Direct Mercator’s straight lines are..
Rhumb lines
Why are the disadvantages of Direct Mercator maps often ignored?
Direct Mercator maps are mostly used for small-scale navigation
What are parallel in Direct Mercator maps?
Meridians of Longitude
What are parallel in Transverse Mercator maps?
Meridians of Longitude
On Mercator maps, what are forced to be equidistant?
Parallels of latitude
On standard CAA 1:500,000 charts, the quadrants are what dimensions
30 minutes x 30 minutes
How many feet in a nm?
6080
In Lambert maps, long and lat cross at
Right angles
All things marked on the aviation char denote the the upper levels as
ALWAYS an altitude in thousands of feet
