gravity32,
the static systems on large transport aircraft are rated to the Mmo of that aircraft and corrected by the air data computer. This is why you will read a calibrated airspeed on most large transports and not an Indicated Airspeed. So the staitic system would be rated to .86 mach. To understand the reasons for Vmo/Mmo click here...
Boeing 757 Boeing :: Vmo/Mmo Limitations Review
The reason you see the altitude diverge as the aircraft gets lower, is because the Radar altimeter only measures from an object underneath the airplane. Whether that be a building, etc. It is impossible to determine a True Altitude from a Radar altimeter unless you know exactly what object you are measuring from. The altitude readout from a Radar Altimeter is known as Absolute altitude. It does not necessarily mean your height above the ground, especially if there are many buildings along the approach corridor. You would expect to see the altitude diverge when descending towards a runway with obstacles along the approach.
When and if you measure from a known object, such as over a runway, the True Altitude lines up pretty well with the Radar Altitude when adding runway elevation. There is no more altitude divergence.
See here:
Debunking Fdr Debunking - Pilots For 9/11 Truth Forum