I would like to specify a few things before starting with my actual question :

* At the equator, the Earth spins at approximately $1000 \ \mathrm{mph}$
* Currently, because we are on the Earth, even we are moving at approximately $1000\ \mathrm{mph}$

My actual question is that, when we fly in a plane, for example, we won't be moving at $1000 \ \mathrm{mph}$ speed anymore right? Assuming your plane is going at $500\ \mathrm{mph}$, would time go 2 times slower?