Alex,
One of the aims of my last post was to point out the fact that your tristar observations (as amended) are exactly as illustrtaed in the CAP 698.
JT
I am sorry if you found my last post a "length and boring dissertaion", but it was not intended to be addressed to experts such as yourself. The initial question clearly required a fairly fundamental approach and that is what I attempted to give in my first post. I unfortunatley made the mistake of not emphasising the fact that real-world situations are often very different.
The CAP 698 is indeed a study guide. It is supplied to JAR ATPL students during their training and is used in the examinations. I believe it is based on a specific aircraft type, rather than a generalised aircraft. This view is based on the fact that it is clearly easier and cheaper to use existing data rather than generate new material. (Rumour has it that the 737 books were used.)
The old CAA performance examination questions were almost all practical exercises using the CAP tables. Since the introduction of JAR, the emphasis has shifted to questions requiring an understanding of why the curves have particular shapes. My earlier posts in this string were intended to address the matter at that level.
Finaly I think it is worth considering why people do or do not post questions in this forum. Some are looking for detailed real-world information about specific aircarft types and situations. Simplistic answers based on ATPL exam-level material are clearly inapropriate here. Adressing such questions should clearly be left to those with the required experiance. But even in these circumstances, we should rememeber the wider readership. Far too many answers are totally incomprehensible to many readers.
For questions with titles such as "Jet transport performance please help", a more fundamental approach is required. Answers such as "there are too many boundary conditions to answer such generalised questions" are unlilkely to be of any value to the originator of the question. A depressingly large number of students tell me that they are not prepared to post quetions on pprune, because they know they will not get an intelligible answer. Conversely, the many who ask me questions by e-mail often comment on how surprised they are at what a simple e-mail can do.