PJ2
Interestinlgy, the altimeters were not affected.
in that case I would suggest it was not the static but the pitot tube itself. That was the case with the Birgenair flight. As they climbed, the static pressure decreased, however, the pressure inside the clogged pitot tube remained largely constant. A higher pressure differential between pitot and static is interpreted as higher airspeed, therefore, the automatic systems pitched up and reduced thrust right into the stall. To make things worse, the crew thought that the stickshaker was really an overspeed effect, with the CPT PFD speed reading way up there. All the time, the backup and the FO airspeed was correct.
A blocked static should have the opposite effect: the higher you climb, the smaller the pressure differential as static pressure remains largely constant (maybe even to the point where static pressure becomes larger than pitot pressure).
I guess we don't disagree much. We're just looking at different areas of potential improvement. It's the swiss cheese model all over again. The hole that represents a radalt failure may be tiny, but in this case, it was perfectly aligned with a number of others. We're just moving different slices ;-) (and all the time hoping that we're not aligning other holes as a result).
Thanks for the interesting discussion.
