Juan,

The F block upgrades the 757 to a very complicated aircraft that requires you to follow checklists and the proper procedures.  

I must say by the question that you asked I could tell that you have not read your manual. [smiley=embarassed.gif]
I would suggest that you read the manual and become familiar with the aircraft and it’s systems and procedures.

Read the manual the answers to your questions are all there! [smiley=thumbsup.gif]