missing aircraft file

hi there im new here but im hoping someone can help
does anybody have a copy of the default aircraft folder for fsx as mine comes up with an error when loading a mission and put me in airtrike not the plane i should be in plz help thanks
does anybody have a copy of the default aircraft folder for fsx as mine comes up with an error when loading a mission and put me in airtrike not the plane i should be in plz help thanks