Hi Doug E style,
We thought that as well that was why a study was made to see if there was a correlation between the number of level change instructions and Level Busts.The study did not find a correlation...
There is however a correlation between level busts and an instruction to climb above the Transition altitude. It does not seem to matter how high above the TA the level is, on a low pressure day level busts will occur. There does seem to be a break down in SOPs and we also think that the error occurs in High pressure but it is not noticed because the aircraft does not reach the cleared level and high pressure is normally closer to 1013 so we wouldn't see the difference very often.
This type of level bust is why LTCC now issues a notam warning of low pressure when it is below 990. because there is not much distance between 6,000ft and the first FL above TA, if you forget to set standard pressure when you are cleared to a FL.
