QNH and Flight Level
Hello, I'm revising for my PPL Nav exam, and I'm stuck on one of the sample questions in my book. It's asking me to select the lowest available flight level which complies with the quadrantal rule. The track is 063 so it's an odd flight level; the corresponding available options are FL30 and FL50. QNH is 1015.
I had answered FL30, but the book says FL50 is correct. I don't get this.
With QNH 1015, the 1013 pressure level is 60ft above msl. Correct? So, if I'm flying with 1013 dialed in and 3000ft indicated, I'm at FL30 which is 3000ft above the 1013 level, i.e. 3060ft amsl. FL30 is therefore above the transition altitude, so is available for use.
Where have I gone wrong? I hope I don't have a fundamental misunderstanding of this stuff.
The explanation in the book has a confusing diagram with the 1015 level appearing above the 1013 level, which I just can't make sense of.