Satcos Whipping Boy:
therefore Decision is made AT decision height but preparations to execute MA are made prior to that point. The MA procedure does cater for a/c dipping below DH. simple really.
That is not quite correct and not so simple, actually. The decision is not an instantaneous event, rather a process of assessments that must be completed by Decision Altitude. The pull-up must be commenced
not later than DA. Provision indeed is made in the procedure for a momentary dip below DA, which in fact may or may not occur.
The concept is not infrequently applied incorrectly.