Aircraft Operations. Volume II - Construction of Visual and Instrument ...

I-4-3-App C-2 Procedures — Aircraft Operations — Volume II
— outbound leg length: L (Table I-4-3-App C-l, line 13)
— radius of turn: r (Table I-4-3-App C-l, line 5).
3.1.2.2 Protection of the outbound leg From “a” draw two lines at an angle of 5.2° for a VOR and 6.9° for an
NDB on each side of the nominal outbound leg. Locate points bl, b2, b3 and b4 on these lines (Table I-4-3-App C-l,
lines 14 and 15). These points determine the area containing the beginning of the inbound turn.
3.1.2.3 Protection of the inbound turn
3.1.2.3.1 With a centre on c2 at a distance r from b2 on the perpendicular to the nominal outbound leg and a
radius r, draw an arc beginning at b2. Locate points d and e after 50 and 100 degrees of turn after b2. Similarly, draw
an arc beginning at b4 and locate point f after 100 degrees of turn after b4 and draw an arc beginning at b3 and locate
points i and j after 190 and 235 degrees of turn after b3.
3.1.2.3.2 Influence of the wind
a) The wind effect is calculated for each point of the turn by multiplying E, the wind effect during one degree, by
the number of degrees of turn;
b) draw arcs with centres d, e, f, i and j and radii Wd, We,Wf ,Wi and Wj (Table I-4-3-App C-1, lines 16 to 19).
The arc centred on f is called arc f;
c) draw a line tangent to the arc centred on e (or f if more conservative) making an angle d (Table I-4-3-App C-1,
line 20) with the perpendicular to the inbound track and locate point k at its intersection with the inbound track.
With a centre on C5 at a distance r from k on the nominal inbound track, and a radius r, draw an arc beginning
at k. Locate points g and h after 50 and 100 degrees of turn after k; and
d) draw arcs with centres g and h and radii Wg and Wh (Table I-4-3-App C-1, lines 16 and 17).
3.1.2.4 Drawing of the protection area of the base turn. The outline of the protection area is composed of:
a) the spiral envelope of the arcs centred on “d” and “e”;
b) the spiral envelope of the arcs centred on “g” and “h”;
c) the spiral envelope of the arcs centred on “i” and “j”;
d) the tangent to the spiral a) passing through “a”;
e) the tangent to the spirals a) and b) or the tangent to the spiral a) and arc f, a portion of arc f, and the tangent to
arc f and b);
f) the tangent to the spirals b) and c); and
g) the tangent to the spiral c) passing through “a”.
Note.— If point a lies within spiral c), the outbound time should be increased.
23/11/06