mi68guel and Check Airman
The blue arrow does not become visible before arming approach or even after arming approach if APPNAV only becomes armed (APPNAV in blue). Only when the APPNAV mode becomes active the blue arrow will appear so the SOP rightly does not say the arrow must be blue when arming approach because it can't be. Conditions for engagement of FINALAPP are not for arming the approach but for FINALAPP to become active mode to begin final descent. If the arrow is not blue it will not descent unless that condition which is not fulfilled gets fulfilled before reaching the final descent point. Sequencing of DECEL is one of the conditions. The aircraft must be in approach phase even if you manually activate approach it's OK.
Last edited by vilas; 4th Jun 2016 at 18:29.