Aeronautical Charts

Question 1

What is the VNC?

Answer 1

• Most common chart you use as a VFR pilot
• VFR Nav Chart
• Designed for low altitudes (3000-8000AGL)
• Scale is 1:500 000 (1 inch = 500K inches on the ground. Or 8SM or 7NM
• Drawn via the Lambert Conformal Conic Projection
• Lines you draw on these maps are Great Circles

Question 1

What are all the Nav Canada published charts?

Answer 1

VNC (VFR Navigation Chart)
VTA
CFS
WAS
DAH
LO
HI
CAP

Question 2

How often are VNC maps updated?

Answer 2

About every two years or when there are enough significant changes in the area that its necessary to draw a new map

Question 3

What is the VTA? VFR Terminal Area Chart

Answer 3

• Used for 3000AGL and lower
• Don’t use them very often (I don’t anyway)
• Scale is 1:250 000 (or 1 inch = 4SM)
• Drawn with the Transverse Mercator Projection
• Any line you draw on this chart is a Rhumb line

Question 4

The VTA is more zoomed in and so has much more detail than the VNC, so why don’t we just use VNCs for navigation all the time?

Answer 4

VTAs are Terminal Area charts. So they only cover airports that have terminal control areas, i.e. big airports like YYC and YYZ.

Question 5

If something new is built between the current map and a new one, where would you find out about it?

Answer 5

• First check the Nav Can website to make sure your map is current
• The check the NOTAMs
• After 56 days, the NOTAM will drop off because it will be put in the Flight Planning section of the CFS
• Check the CFS

Question 6

**What is a Lo Chart?

Answer 6

• Designed for IFR flights
• Surface to 18000ASL
• Scale varies from chart to chart, so you have to check the bottom of the map to find out what scale is being used
• Lines you draw on this map are Great Circles
• Drawn with the Lambert Conformal Conic Projection
• Valid for and updated every 56 days

** These dont have many topographical features and show radio aids, airports, and other points of interest

Question 7

What is a Hi Chart?

Answer 7

• Also IFR (Jets, turboprops)
• All the same info as the Lo Charts but are for 18000ASL and higher

Question 8

What is the CAP? Canada Air Pilot

Answer 8

• For IFR arrival and departure info
• Contains instrument approach procedures/noise abatement/ departure procedures
• Published every 56 days (just like Lo, Hi, and CFS)

Question 9

What is the WAS?

Answer 9

• Water Aerodrome Supplement
• The CFS for water
• Published once per year

Question 10

What is the DAH?

Answer 10

• Designated Airspace Handbook
• Little known but valuable book
• Info on CYA and CYR etc airspace you might want to fly past or through.
• Published every 56 days
• Is free on the internet

Question 11

What is the Lambert Conformal Conic Projection?

Answer 11

Used for VNC, Lo, and Hi charts

Lines on this map are Great Circles

Basically if you stuck a cone of paper over the top half of the earth and projected it onto the paper, then took it off and did your best to lay it flat

Question 12

What are Standard Parallels?

Answer 12

The spot where the cone of paper would actually touch the globe. In these areas of the map, distortion will be at a minimum

Question 13

A straight line drawn through two meridians of longitude on a Lambert Coninc Projection map (VNC, Lo, Hi) is a Great Circle. By how many degrees must you change your heading as you fly to stay on this track?

Answer 13

Change heading by 2° for every 3° of longitude

It is the opposite of correcting for variation. So if you are flying east, the 2° is added. Flying west, it is subtracted

Question 14

What is the Mercator Projection?

Answer 14

Place a cylinder of paper around a globe. Put a lightbulb in the center of the globe. The shadowns cast on the cylinder of paper are your map

Question 15

What is the biggest problem with Mercator Projection? (VTA)

Answer 15

The farther you get from the equator, the worse the distortion will be. Which is why Greenland looks as big as all of North America on one of these charts. The distortion in the far north is extreme

Question 16

What is a straight line drawn on a Mercator Projection (VTA) map?

Answer 16

A Rhumb Line. This is because on this type of map, meridians of longitude and parallels of latitude are both straight and parallel

Question 17

If the Mercator Projection distorts more of the map as you move North, how can we still have uniform scale across these types of charts?

Answer 17

By taking small sections, the scale can be adjusted. It would only be an issue if you have a huge chunk of map say from the equator to Canada