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

Part I — Section 4, Chapter 3, Appendix C I-4-3-App C-11
3.3.3.1.1.2 Procedure overhead an NDB
a) Locate point “A” on the NDB; and
b) draw around “A” the position fix tolerance area of the NDB given by the template (area Nl N2 N3 N4) and
locate points “Al”, “A2”, “A3” and “A4” on the four corners of this area.
3.3.3.1.1.3 Procedure at the intersection of VOR radials
a) Locate point “A” at the intersection of the homing and intersecting radials; and
b) draw around “A” the position fix tolerance area determined by the tolerances of the homing and intersecting
radials Part I, Section 2, Chapter 2, 2.3.3, “System use accuracy” and locate points “Al”, “A2”, “A3” and “A4”
on the four corners of this area.
3.3.3.1.2 Construction of the procedure area
3.3.3.1.2.1 Place the template point “a” on A3, with the template procedure axis parallel to the inbound track, and
draw the curve “3” (part of the outline of the template) and the line “3” (protection of the outbound leg in the direction
of the D axis).
3.3.3.1.2.2 Place the template point “a” successively on “Al”, “A2” and “A4” to draw curves “l”, “2” and “4”.
3.3.3.1.2.3 Draw the common tangents to curves “l” and “2”, “2” and “4”, “3” and “4”, “3” and “1”.
3.3.3.2 Construction of the entry area
3.3.3.2.1 Construction of the entry area assuming omnidirectional entry overhead a VOR or an NDB
3.3.3.2.1 (Reference Diagrams I-4-3-App C-10, I-4-3-App C-11 and I-4-3-App C-12)
3.3.3.2.1.1 Draw the circle centred on “A” passing through “Al” and “A3”.
3.3.3.2.1.2 Locate point “E” on a series of points along this circle (with the template axis parallel to the inbound
track) and for each point draw a curve at the outer limit of the template in the direction of the C and D axis; curve “5” is
the envelope of these curves.
3.3.3.2.1.3 Draw the limit of the entry sectors 1 and 3 (line making an angle of 70° with the inbound track). With
the template axis on this line, draw the entry fix tolerance area El E2 E3 E4 given by the template for the VOR or the
NDB.
3.3.3.2.1.4 Place the template point “a” on El and E3 (with the template axis parallel to the separating line of the
sectors 1 and 3) and draw curves “6” and “7” and their common tangent.
3.3.3.2.1.5 With a centre on “A”, draw the arc tangent to curve “6” until intersecting curve “1”.
3.3.3.2.1.6 Line 8 is the symmetric of lines 6 and 7 about the 70° dividing line. Draw common tangents to curves
“5”, “6”, “7” and “8” as appropriate.
23/11/06