It always makes me question the personal and flying skills (after all it does involve a minimum of intelligence & thinking) if people ask these very basic questions without even attempting to read the information, that has already been posted here, hundreds of times.
Do you people really think, you are the first ones to come up with these question?
Why don't you simply use the search function of this forum.
a thread, that might answer your questions might include
http://www.pprune.org/african-aviati...2010-11-a.html
