ATPLS Law and OP - memory aids

[Matron]

I'm currently studying for Law and OP for the September ATPL exams. Given the large volume of info to commit to memory I was wondering if anyone could help me with an 'aide memoir' or two that they may have picked up whilst studying.

I'll get the ball rolling with some things that I've found useful:

1. Air Law: Number of stripes required on a runway threshold is approximately equal to one quarter of the runway width - rounded up or down...

Runway width --- Stripes required
18m ------------ 4
23m ------------ 6
30m ------------ 8
45m ----------- 12
60m ----------- 16


2. OP: Longitudinal separation in NAT using mach number technique can be between 10 and 5 minutes depending on how much the lead aircraft is faster than following aircraft. A handy memory hint for the table below is that each pair of numbers add up to "11" - if you see what I mean...

Separation (mins) --- Lead aircraft faster by
9 ------------------ M0.02
8 ------------------ M0.03
7 ------------------ M0.04
6 ------------------ M0.05
5 ------------------ M0.06


Best wishes to all for September exams.