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Flightsurgeon created the topic: take off distance required please help
My answer was 940 and the correct answer 950
Try as I might Im not getting some of these
the difference between 940 and 950 is very minimal and also I looked at your solution and magnified the image
It seems the red line lies to the left of midline indicating a value slightly above 950 more like 960
How precise does this have to be
I think my method is exactly the same but the tool is the problem. Unless the chart is magnified, then the answers are not going to be accurate as extremely minor deviations are going to put us out.
John.Heddles replied the topic: take off distance required please help
These old DCA charts (and any other formats) were never intended to be used to that sort of accuracy and repeatability. There is never any practical need to go to the extent of scanning up the chart size. They are intended to be used as is albeit with a modicum of diligence and a sharp pencil.
Try redoing the question using, say, a sharp 2H lead and repost for comment. The thick lines are a bit self-defeating, although you may well have just run them over the sharp pencil solution for the benefit of the scan and post.
Engineering specialist in aircraft performance and weight control.
bobtait replied the topic: take off distance required please help
It breaks my heart to see all the frustration and heartache being caused by the ridiculous degree of accuracy CASA expect in the use of P Charts and Centre of Gravity envelopes.
This nonsense has surfaced since CASA changed from multi-choice answers to 'type-in' answers for these questions. I'm afraid it simply goes to support the suspicion that the questions and/or the marking protocols are not the work of anyone who has actually flown an aeroplane.
As John points out, the purpose of the charts was to give a pilot a simple and reliable way to confirm that the intended operation can be conducted with appropriate safely margins. It should take no more than 2 minutes to do that and it certainly was never intended that you should use a photocopier to enlarge the chart and then use a T square and set square to draw lines with the very sharpest of pencils.
Because these questions are worth more than one mark, and an exam often contains up to 4 or 5 such questions, it is often the difference between passing and failing for competent and well prepared candidates.
I know this post is not much consolation to many who have suffered the consequences - but it needs to be said.