NAV 3 & 4 Flashcards
Do meridians run top to bottom or left to right of a globe
Top to bottom
Does latitude run top to bottom or left to right of a globe
Left to right, in line with the equator
Does longitude run top to bottom or left to right of a globe
Top to bottom, runs through Greenwich
On a map what is a projection
Projecting a portion of a sphere (earth) onto a flat surface
Why can there not be a perfect projection of the earth onto a flat surface
Irrelevant of what projection is used there will always be a distortion of some kind
In nav what is a chart
A projection with additional information for a practical need, such as bare landmass with airways
In nav what is a map
Projection with essential geographical and topographical features. Additional aeronautical information may be overlaid to satisfy a need
What are three examples of cylindrical projection
1) Mercator projection
2) Transverse Mercator
3) Oblique Mercator
What is a Mercator (conformal) projection
Upright cylinder. North/South alignment
Meridians at longitude
At equator rhumb lines & great circles both appear straight
What is a Transverse Mercator projection
Cylinder on side, aligned to parallels of latitude
What is a Oblique Mercator projection
Cylindrical conformal map but the cylinder is wrapped around the ellipsoid so it touches the surface along the great circle for a chosen central line instead of the equator
What is conic projection
Cone placed over a globe touching equal points of a meridian of latitude
Very accurate for areas near the parallel
What is the full name of the conical projection
Lambert’s conformal conic projection
In NAV what is UTM in projections
Universal Transverse Mercator. Make 60 wedges for each UTM zone
In maps, what 5 characteristics are subject to distortion
1) Shape
2) Distance
3) Direction
4) Scale
5) Area
In maps, how do lines of latitude and longitude intersect on a map where shape is preserved
Intercept at right angles. Maps that keep shape are conformal projections
A map that can preserve distance from the centre of projection to all other points are called what
Equidistant. Distance between meridians are maintained
When a map is able to maintain direction what can be said about the angles of lines on the map
Angles from the central point or point on a line are preserved and portrayed correctly
What is scale in relation to a map characteristic
Ratio between a distance on a map vs the same on earth. No projection can maintain scale over large areas, but some can within 1%-2%
What is a map described as equal-area or equivalent
A map that can portray areas in proportional relationship to area on earth
What are the 5 properties of an ideal map in NAV
1) No distortion. Conformal, preserving shape and area at every point
2) Preserve angular relationships
3) Accurate size
4) Reasonably constant scale across whole chart
5) great circles and rhumb lines shown as straight lines
In a Lambert conical cone projection what are the visual elements of the meridians and parallels
Meridians are straight lines converging to the pole. Parallels are concentric circles centred to the nearest pole
In a Lambert conical cone projection what is the major benefit in relation to great circles
Great circles appear straight
In a Lambert conical cone projection what are some examples of its uses
Navigation, topographical mapping, geological mapping
What are some properties of a Lambert conical cone projection
Reasonably accurate
Distances = true
Distortion of shapes and area minimal
Preserve angles locally but not necessarily lengths
In a Mercator projection, what are the properties of the meridians and parallels
Both straight lines. Meridians equidistant, parallels increase in distance away from equator
What shape are rhumb lines on a Mercator projection
Straight lines, great circles are bent
In a Mercator projection, what can be said about direction and distance
Directions are true on any straight line. Distances are true only on the equator
In a stereographic projection, what are the properties of the meridians and parallels
Meridians project straight lines from the pole. Parallels are concentric circular arcs
What type of chart is needed to navigate round an airport
Aerodrome chart
What are some features of an aerodrome chart
Runways, taxiways, aprons, parking positions
What scale of maps do VFR flights typically use
1:500,000
What types of charts would an IFR pilot carry that a VFR pilot is less likely to carry
SID’s
STAR’s
Approach charts
In maps, what does a SID show
Standard instrument departure, standard departure route for an aircraft departing under IFR. Approved pre planned route
What three features may be found on an en-route chart
Route names
VOR’s
Waypoints
What features may be found on an approach chart
Tracks to fly
Ranges
Levels
What is an approach chart trying to achieve
Guide an IFR aircraft to a specific runway using a specific approach aid
What is this symbol on a chart showing
Aerodrome - Civil
What is this symbol on a chart showing
Aerodrome - Civil with limited or no facilities
What is this symbol on a chart showing
Aerodrome government. Available for civil use
What is this symbol on a chart showing
Aerodrome - Government
What is this symbol on a chart showing
Microlight flying site
What is this symbol on a chart showing
Disused or abandoned aerodrome
What is this symbol on a chart showing
Training aerodrome, expect flight training and circuits
What is this symbol on a chart showing
Aerodrome unusual activity. Aerobatic/formation flying
What is this symbol on a chart showing
Aerodrome traffic zone (ATZ)
What is this symbol on a chart showing
Customs aerodrome
What is this symbol on a chart showing
DME
What is this symbol on a chart showing
VOR
What is this symbol on a chart showing
VOR/DME pair
What is this symbol on a chart showing
UHF tactical air navigation aid (TACAN)
What is this symbol on a chart showing
NDB
What is this symbol on a chart showing
Maximum elevation
What is this symbol on a chart showing
Air traffic service unit area
What is this symbol on a chart showing
Radar advisory service zone
What is this symbol on a chart showing
Transponder mandatory zone
What is this symbol on a chart showing
Radio mandatory zone
What is this symbol on a chart showing
Reporting point
What is this symbol on a chart showing
Exceptionally high obstacle (lighted)
What is this symbol on a chart showing
Compulsory reporting point
What is this symbol on a chart showing
Single obstacle (unlit)
What is this symbol on a chart showing
Multiple obstacle (lit)
How does a UKVFR 1:250,000 chart differ from a 1:500,000 chart
1:250,000 more detailed. for GA flying, 8 maps of the UK & NI
What details does an IFR High alt mostly show
Nav positions (VOR & NDB), route names, 5 letter waypoints
What details does a mid level chart mostly show
Airspace classification & restrictions. More info than high level chart
What is the use of an aerodrome chart
Navigate taxiing around an aerodrome
What is the use of a VFR 1:500,000 chart
Navigate airspace boundaries
Restricted areas
Danger areas
Navaids
What is the use of a VFR 1:250,000 chart
Slower aircraft/local flights wanting more detailed map
How is true air speed defined
The speed in knots of an aircraft relative to the airmass being travelled through
What three measurements are used to express direction
True, magnetic or compass relative to north
In nav what two ways can be used to describe and aircrafts velocity in a given direction and speed
1) Over the ground. Combination of the track over the ground and groundspeed. Track 045° Groundspeed 250kts
2) Through the air
Combination of the heading through the air and true air speed
Heading 040° True Airspeed 270 kts
How does heading and track differ
Heading is where the aircraft is pointing. Track is the direction of travel of the aircraft relative to the ground
In nav, what is an aircrafts drift angle
Difference between heading and track
In nav what is the triangle of velocities
Using aircraft heading, TAS and wind velocity to find track and groundspeed.
Allows heading to be calculated factoring in the wind to achieve a desired track
In what unit are forecast winds reported
Degrees true
How is calibrated airspeed defined
Indicated airspeed corrected for instrument and position error. Normally very similar to indicated airspeed
How is groundspeed defined
Aircrafts horizontal speed relative to ground
How is indicated airspeed defined
Airspeed read directly from airspeed indicator
How is Mach number defined
Ratio between true airspeed and local speed of sound
How is true airspeed defined
Actual speed of aircraft relative to the air mass within it is flying
What airspeed measurement could be considered the most pertinent
Indicated airspeed. What pilot uses for reference to stall speed, flap setting & rotation speeds. It is the speed ATC instruct to be flown
What two tools are used on an aircraft to calculate indicated airspeed
Difference between static and dynamic air pressure
What two major factors affect dynamic pressure an aircraft experience in flight
Speed and air density
What is true air speed accounting for that indicated airspeed is not
True accounts for altitude and atmospheric conditions. Useful for finding groundspeed as it equals true +/- wind speed
How does the Mach number change with altitude
Increase in altitude, decrease temperature so speed of sound decreases
What speed measurement is used to separate aircraft above FL290
Mach number
What four speed measurements are used in ATC
Mach number
IAS
TAS
Groundspeed
What speed measurement do controllers use to separate aircraft below FL290
IAS
What is the use of true air speed (TAS) for controlling purposes
Flight planning, used on strips and flight plans
What airspeed is used for the initial and final stages of flight
Indicated air speed
What airspeed is used for navigation at cruising altitude
True air speed
What three errors may indicated air speed suffer
1) Instrument error. Faults in construction and calibration
2) Position error. Pitot tube at inaccurate angle
3) Density error. AKA height or temp error
What aircraft speed may be typically displayed on a radar screen
Groundspeed. As reported by transponder/radar
