Convergency Flashcards
Explain what convergency is
The angle of inclination between two meridians at the same latitude, or the change in direction that a great circle experiences over its length
Earth convergency is the angle between ___
The tangents to two meridians
Convergency Formula
Delta Longitude x Sin( Mean Latitude )
Chart convergency is the angle between ___
meridians on a projection
Explain what the convergency factor is
The number of degrees change in track bearing per degree travelled
On a Mercator the chart convergency is _
0
Sin( Parallel of Origin) on a Lambert Conical projection gives you the ___
constant of the cone
Outline the method to calculate a rhumb line distance and direction between two coordinates
CALCULATE DEPARTURE Dep(NM) = ChLong' x Cos( MLat ) ---------- CALCULATE THE COURSE Tan( Crs ) = Departure / ChLat' 360 - Crs ---------- CALCULATE THE DISTANCE Distance = Departure / Sin( Crs )
Variation and conversion will always need to be applied where ___
bearing is measured, work is done
If using an ADF, apply variation and conversion angle at the ___
aircraft - that’s what’s measuring the RB to the station
If using an VOR apply variation and conversion angle at the ___
station
The true direction of a vertex on a great circle is always ___ or ___ degrees
90 or 270
