unlikely occurrence?
Belgique says:
"But then again, would they have been testing for an unlikely "sometime" occurrence (such as an accumulation of water in the static lines)"
Rather than "unlikely" I might have said "unanticipated". Probably no manufacturers would water a static line and go out and flight- test for such a condition. However in my experience some aircraft are more likely than others to draw water into their static lines. It would be interesting to know:
a. How much they normally find in an A300 (and whether recods are kept)
b. Whether they check it after an aircraft wash (most companies wouldn't, they'd just trust that taping over the ports would ensure that no water got in).
c. Whether water can accumulate inflight (due to flight through heavy precipitation - or be drawn in on descent as airframe icing melts.
d. What parameters American Airlines use for mandatorily chucking the bungs in (overnight parking only - or at all other times?)
I think I'm right in saying that low points are normally provided as water traps (with drains fitted) at some point before the port and starboard static lines are Y'd (or T'd) together. Water accumulating in those low points MUST affect the air pressure being sensed by the transducers further downstream in the lines (or at the CADC itself) - particularly during rapid yawing, when the water flows would be in opposite directions on the port and stbd sides..
I'll leave it up to your imagination as to what effect this hydro-pneumatic damping might have upon the static pressures being sensed at the CADC (and more importantly what effect a pulsing pressure [that's usually fairly constant] might have upon the airspeed outputs being provided to other aircraft systems - including most importantly the yaw damper). This is where "sampling rates" start to confuse the issue and you'd really need to go out and conduct experiments to get to a bottom line.