Most if not all of them slide left, is the centrifugal force of the blades. Mine lifts straight off now, but it's only because I'm inputting to correct it without even thinking about it now. Once you get her in the air if she is still moving left you might have a trim issue.
It's a lot of reading but this thread covers almost everything for a FP machine http://www.rcuniverse.com/forum/m_6807677/tm.htm