Text 29

CHAPTER 19. PLOTTING CHART - ICAO

Part 1

19.1 Function

19.1.1. This chart shall provide a means of maintaining a continuous flight record of the aircraft position by various fixing methods and dead reckoning in order to maintain an intended flight path.

19.2. Applicability

19.2.1. Recommendation.- This chart should be made available, in the manner prescribed in 1.3.2, to cover major air routes over oceanic areas and sparsely settled areas used by international civil aviation.

Note.- In areas where the Enroute Chart - ICAO is provided there may be no requirement for a plotting chart.

19.3. Coverage and scale

1. Recommendation. - Where practicable, the chart for a particular region should cover major air routes and their terminals on a single sheet.

2. Recommendation. - The scale should be governed by the area to be covered.

Note. - Normally the scale will range from 1:3000000 to 1:7500000.

19.4. Format

19.4.1. Recommendation.- The sheet should be of a size that can be adapted for use on a navigator’s plotting table.

19.5. Projection

19.5.1. Recommendation.- A conformal projection on which a straight line approximates a great circle should he used.

19.5.2 Parallels and meridians shall be shown.

19.5.2.1. Recommendation.- The intervals should be arranged to permit accurate plotting to be carried out with a minimum of time and effort.

19.5.2.2. Graduation marks shall be shown at consistent intervals along an appropriate number of parallels and meridians. The interval selected shall regardless of scale, minimize the amount of interpolation required for accurate plotting.

3. Recommendation.- Parallels and meridians should be numbered so that a number appears at least once every 15 cm (6 in) on the face of the chart.

4. If a navigational grid is shown on charts covering the higher latitudes, it shall comprise lines parallel to the Meridian or anti-Meridian of Greenwich.

Questions:

1. What is the function of the chart?

2. What is the applicability of the chart?

3. What should the format of the chart be?

4. What projection should be used?

Text 30

CHAPTER 19. PLOTTING CHART - ICAO

Part 2

19.6 Identification

19.6.1. Each sheet shall be identified by chart series and number.

19.7. Culture and topography

19.7.1 Generalized shore lines of all open water areas, large lakes and rivers shall be shown.

19.7.2 Spot elevations for selected features constituting a hazard to air navigation shall be shown.

19.7.3. Recommendation.- Particularly hazardous or prominent relief features should be emphasized.

Note.- Large cities and towns may be shown.

19.8. Magnetic variation

19.8.1. Isogonals or, in higher latitudes, isogrivs, or both, shall be shown at consistent intervals throughout the chart. The interval selected shall, regardless of scale, minimize the amount of interpolation required.

19.8.2. The date of the isogonic information shall be shown.

19.9. Aeronaulical data

19.9.1. The following aeronautical data shall be shown:

1) aerodromes regularly used by international commercial air transport together with their names;

2) selected radio aids to navigation that will contribute to position-finding together with their- names and identifications;

3) lattices of long-range electronic aids to navigation, as required.

Questions:

1. How should the chart be identified?

2. What natural and cultural landmarks be shown?

3. How shall isogonals and isogrives be shown?

4. What aeronautical data shall be shown?