Spoilres...

The spoilers are generally used to loose altitude fast.

You use them in two ocasions: 1- During a landig approach 2 - when you are high in a thermo and want ot loose altitude.

What they do: Once your spoilers are up they will intrupt the airflow over the wing causing the wing to become ineficient with the result of a rapid loss of altitude.

the air attaches to a wing like a glove and flows over and under it maintainig the plane a float. The airflow is normally laminar. This means it flows over very close to their surface with out generating turbulence. Using any interuption it will release that air bubble and make it turbulent. This can be beneficial if you want more reaction on you flying surfaces...elevator, airlerons this why the turbulators where invented. With the spoilers this interuption is very drastical causing big waves over the wing with the result of abrupt loss of lift.


Saludos,
Landi