1) The constant of cone of a Lambert conformal conic chart is quoted as 0.3955. At what latitude on the chart is earth convergency correctly represented?
a) 66°42'
b) 23°18'
c) 68°25'
d) 21°35'
Constant of the cone is the same as the sin of the parallel of origin. So inverse sin of 0.3955 equals 23.297, which if you convert to degrees and minutes is 23° 17.5' Answer (B)
2)
The constant of the cone, on a Lambert chart where the convergence angle between longitudes 010°E and 030°W is 30°, is:
a) 0.40
b) 0.75
c) 0.50
d) 0.64
Convergence angle = change in longitude X constant of the cone.
Or,
30° = 40° X constant of the cone --> 3/4 or 0.75 Answer (B)
3) Distance A to B = 120 NM, After 30 NM aircraft is 3 NM to the left of course. What heading alteration should be made in order to arrive at point 'B'?
a) 8° L
b) 6° R
c)4° R
d) 8 R°
Ok, we're 3NM off track after 30NM so after 60NM we would be 6NM off track which we know from the 1 in 60 means we have 6 degrees of track error.
To close back onto track we need to regain 3NM in 90, which is the same as 2NM in 60 if you divide both numbers by 1.5. So our closing angle equals 2 degrees.
Track error plus closing angle is the number we want, which is 8 degrees, and now we just have to decide left or right. If we're left of track then we're going to have to turn right to get back to it. Answer (D)
Hope this helps,
Streety.