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I found a sample question from CASA IREX sample questions. I am not able to find it from AIP.
You are flying in G airspace but the track takes you near CTA. Flight condition is IMC, and your only means of navigation is by NDB. To ensure your intended flight path does not violate CTA, you should plan to avoid the relevant boundary by a minimum of –
But the question is asking " avoid the relevant boundary by a minimum of ? " According to Bob "avoiding CTA except to remain 'well clear' or alternatively, get a clearance". But the question is looking an answer "minimum something" Isn't it? Can it be well clear?
...Sample questions were valid at the time of posting on the CASA web page, though some, especially those which requires referencing to a particular ERC, TAC or DAP chart, could have been rendered out of date by now due to regular amendments of air publications...
In plain language, those sample questions are too old.
Since the distances were removed from the AIP, just stay outside without a clearance. The practical answer is that you check the ADF/NDB tracking tolerances in the AIP and use that as a tracking pad to give you a pretty good chance of missing the boundary. In the current litigious world, maybe give yourself a tad more. However, the question answer alternatives will give you an option (probably select the nearest correct answer) so you need to know where to start from - which will be the aid tracking tolerances.
Engineering specialist in aircraft performance and weight control.