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John.Heddles replied the topic: Take off weight chart
Trap for old players!
There are two groups of players in any activity. Those who have made mistakes in the past (ie all of us) and those who are at risk of making mistakes in the future (ie all of us) ... à la tienne !
As a more general comment, everyone needs to be very attentive to ensuring that
(a) values interpolated (eg heights, distances, etc.) are done so with painstaking accuracy - especially for the exams. Particularly when we are dealing with sloping lines, small errors can be amplified at the next intercept and the final answer can be way off the mark. For a tick the box computer test, that can lead, very easily, to nil marks for the particular question.
(b) all lines carried forward are done so parallel to the background grid, again with painstaking accuracy and for the same reason. Use of a Douglas protractor (or similar) so that the protractor and chart grids can be aligned accurately is highly recommended. Same applies to completion of trim sheets and the like
(c) specifically, for takeoff and landing charts, ALWAYS check if there is a climb weight limit chart and, if such exists, make sure that both the distance limited and the climb limited weights are determined. Note that not all charts will have climb weight limits - these will exist only if the aircraft has a climb problem (usually presented for hot and high conditions). The climb limit chart may be incorporated into the distance calculations (as for the Echo P-chart) or shown as a separate chart. Obviously, in the former, the drafter simply overlays the two to save on page real estate.
Engineering specialist in aircraft performance and weight control.