Originally Posted by
drpixie
He was very clear that if I did the question is the "correct" manner, I'd get the "correct" answer. The correct manner is partially specified by the ATPL exam guide (it does specify temp and weight rounding clearly) - but the guide doesn't specify how to interpolate winds, so I'm not sure what magic method he used to get the correct answer. My thoughts, magic method #1: always extrapolate accurately to exactly 1/2, 2/3 or the FL required. Magic method #2: use F185 for descent, F235 for climb, use nearest for cruise. Magic method #3: some combination of #1 and #2.
Good post DrPixie. I don't know whether the ATPL exam guide was around when I did mine, but it seems like it's only a partial guide. Why can't CASA produce a fully worked example in the guide so that everyone, and every course provider, is on a level playing field? This way, candidates can be assured that they're being examined on the objectives of the syllabus. As it is, it appears those who fail, fail due to some arbitrary method of extrapolating data, such as the example you provided.
When I did flight planning, I used AFT but also bought Rod Avery's notes and they both used very different methods with different 'rules of thumbs' resulting in slightly different answers.