Hello,

Exercise 9 (Page 43)

I am finding it very difficult to get my head around the last part of each question where you find ADF at Intercept. For example in Q1, it states "ADF at intercept -30F = 150degreesR", and I am having a blank on how to get this answer of 150degreesR. If anyone can further explain/help me with answering the questions in the exercise it would be greatly appreciated.

Thanks.

G'day Pilot,

In the terminology of the HAT trick in the book, 270 through north to 090 would be the "TO" hemisphere and 270 through South to 090 would be the "FROM" hemisphere (see below). Therefore, -30F means 30 degrees in the "MINUS" quadrant of the "FROM" hemisphere. That would mean the needle was pointing to 150 degrees on the fixed card ADF, or, in other words, 150 degrees relative.

Similarly, +30F would be 30 degrees into the "PLUS" quadrant of the "FROM" Hemisphere which means the needle points to 210 degrees relative on the ADF.

+30T is 30 degrees into the PLUS quadrant of the TO hemisphere which would be equivalent to 030 degrees relative.

-30T is 30 degrees into the MINUS quadrant of the TO hemisphere which would be equivalent to 330 degrees relative.

Perhaps this diagram will help:

Cheers,

RIch

Thanks a heap Richard. Understand it much better now.