I had previously thought this boat was uninhabited, it is nice to know there are other crewmembers about. Recently it seems that the boards have been used as quick reference material for persons not wanting to do their homework, whether for interview preparations or an impending ATP test. It has become annoying to see multiple questions on the same subject, it would appear that even a simple electronic search is too bothersome. Before throwing stones in my own glass house, I shall quit my ranting.
Answers.
1. In heavy rain the most dangerous condition on final approach is the potential of a microburst if talking about convective type clouds. In heavy rain induced by stratiform clouds the lift and drag penalty of the attached water film on laminar type wings, and the momentum penalty are dangerous aerodynamic hazards. Significant roughness occurs at rainfall rates exceeding 150 mm/hr, while the momentum penalty becomes apparent for large transport category aircraft at 500 mm/hr.
2. For conventional aircraft: As speed increases beyond Mcrit the center of pressure moves aft toward the np, the airfoil produces a nose down pitching moment that must be countered by a change in cg (pumping fuel) or stab setting.