Aeronautical Charts

Question 1

VNC

Answer 1

● VFR flights in the low to medium altitudes.
● Lambert Conformal Conic Projection.
● Straight lines drawn on this map are great circles. (MUST KNOW)
● Scale is 1: 500 000 or 1 inch to 8 SM.

Question 2

VNC Validity

Answer 2

● Validity dates are based on significant changes.
➢ When there are enough changes a new VNC is produced.
➢ On average they are updated every 2 years

Question 3

VFR Terminal Area Chart VTA

Answer 3

● VFR flights at low altitudes.
● Transverse Mercator Projection.
● A straight line drawn on these charts is a rhumb line.
● Scale is 1: 250 000 or 1 inch to 4 SM

Question 4

VTA Validity

Answer 4

● Validity dates are based on changes.
➢ When there are enough changes, a new chart is produced.
➢ On average, this chart is updated every 2 years

Question 5

Chart Validity and Updates

Answer 5

● Imagine a tower is built between the two year chart publishing cycle…
➢ How will we know that it is there?
● First, check http://www.navcanada.ca and look under Aeronautical Information Products:
➢ Check if your chart is valid and current.
➢ It will also list the next anticipated publishing date.
● Next, check the NOTAMs.
➢ Any new obstructions, airspace changes, or revisions to charts will be given in the NOTAMS, unless…

● It has moved to the CFS in Chart Updating Data Section.
➢ New obstructions will run in NOTAMs until the next CFS.
● Finally, check the CFS:
➢ Look in the section called FLIGHT PLANNING.
➢ Obstructions and airspace changes that were previously in a NOTAM will be found in this section.
● As soon as the new chart is published they take the information out of the Flight Planning section in the CFS (which were NOTAMs earlier) and put it on to the new chart

Question 6

Lo Chart

Answer 6

● IFR flights at low altitude, for use below 18 000 feet ASL.
● Lambert Conformal Conic Projection (straight lines are great circles).
● Scale varies from chart to chart.
● Depicts radio aids, airports and other points of interest to aviation but NO topographical features

Question 7

Lo Chart Validity

Answer 7

● These charts are valid for 56 days.
● Dates of validity are stated on the front

Question 8

Hi Chart

Answer 8

● IFR flights at high altitude, for use at 18 000 feet ASL and above.
● Lambert Conformal Conic Projection (straight line is a great circle).
● Scale varies from chart to chart.
● Depicts radio aids, airports and other points of interest to aviation but NO topographical features

Question 9

CFS

Answer 9

● A joint civil and military publication which contains all registered and certified Canadian aerodromes.
● Also contains information on North Atlantic aerodromes.
● It is revised and reissued every 56 days and is available in French or English.

Question 10

CFS Sections

Answer 10

● General
➢ Includes tables, legends and associated information pertinent to interpretation of the supplement.
● Aerodrome/Facility Directory
➢ Data and sketches for Canadian aerodromes and heliports and selected aerodromes in the North Atlantic

● Planning
➢ Information for flight planning, characteristics of airspace, chart updating, flight restrictions, IFR routes, airway intersections and chart distributors.
● Radio Navigation and Communications
➢ Data for radio navigation aids and communication facilities.
● Military Flight Data and Procedures
➢ Flight procedures and data, including sections on procedures for flight in the USA, North Atlantic and Alaska, air/ground communications and military training routes/areas.
● Emergency
➢ Emergency procedures

Question 11

CAP

Answer 11

● CAP information is pertinent to IFR arrivals and departures.
● Contains
➢ Instrument Approach Procedures
➢ Standard Instrument Departure Procedures
➢ Noise Abatement Procedures
● It is amended and reissued every 56 days.

Question 12

Water Aerodrome Supplement WAS

Answer 12

● WAS is a publication that provides tabulated textual data and graphical information to support Canadian VFR charts.
● It contains an aerodrome/facilities directory of all water aerodromes shown on Canadian VFR charts.
● Also listed are communications stations data, radio aids and other data supplemental to the VFR charts.
➢ Revised and reissued annually

Question 13

Designated Airspace Handbook DAH

Answer 13

● DAH lists all the airspace and classes in Canada.
● Little known but VALUABLE book.
● Answers the question “Who do I contact for that CYA or CYR that I fly past?”
● Valid for 56 days

Question 14

Lambert Conformal Conic Projection

Answer 14

● The basic idea upon which the Lambert Conic Projection was developed is that of taking a cone and having it superimposed over the surface of a sphere.
● If the cone were opened and unrolled, then the meridians and parallels would appear like this
● The angles between meridians and parallels will be the same on the chart as they are on the ground.
➢ The term conformal refers to this characteristic

Question 15

Properties of the Lambert Projection

Answer 15

● Meridians of longitude are lines that converge as they get nearer to the pole.
● When put on a Lambert Conical map this curvature is often so small as to be virtually unnoticeable.
● The angle which one meridian makes with another on the Earth is called convergency.
➢ Convergency varies with latitude.
➢ At the equator there is no convergence between meridians.
➢ At the poles the meridians converge at angles equal to the change of longitude between them

● Parallels of latitude are curves which are concave towards the nearest pole.
➢ With Lambert Conical the curvature of these latitude lines can become considerable.
● As for the scale, the distances are practically uniform throughout the entire map sheet.
➢ The maximum distortion is not more than 1/2 of 1%.
● A straight line drawn between any two points on this type of chart represents an arc of a great circle

● Since a great circle does not cross every Meridian of Longitude at the same angle, a straight line on the charts will not have the same bearing when measured on two or more different meridians.
● Hence a straight line, or great circle route, cannot be flown without changing heading at regular intervals.
● To make good a given track or straight line on this type of chart, it is necessary to change heading 2 ̊ for every 3 ̊ of longitude (you’re flying an arc).
➢ Flying east the 2 ̊ is added.
➢ Flying west the 2 ̊ is subtracted

● For flights up to roughly 300 miles the heading change referred to above may be averaged by measuring the course or track on the meridian nearest the centre.

Question 16

The Mercator Projection

Answer 16

● The principle on which the Mercator Projection is based is that of a cylinder which has its point of tangency at the equator.
● Its approximate form may be visualized by imagining a light at the centre of a globe that casts a shadow of the meridians and parallels on a cylinder of infinite length enclosing it.

● The shadows of the more northerly parallels of latitude will be cast wider apart on the cylinder than they actually are on the sphere.
● The shadows of the meridians on the cylinder will be straight and parallel lines to infinity, whereas on the sphere they converge to meet in a point at the poles.
● It is as though the meridians were stretched apart at the poles to the same distance they are apart at the equator.
● This causes extreme exaggeration of meridians in northerly areas.

The principal characteristics of the Mercator Projection are:
➢ Meridians of Longitude are straight and parallel lines.
➢ Parallels of Latitude are straight and parallel lines.
➢ A straight line drawn between any two points on the chart will represent a rhumb line.
➢ Owing to the method of projection there is no constant scale of distance on a Mercator chart and areas are greatly exaggerated in high latitudes