Does the pressure fluctuate when controlled by the safety valve?
I had thought of just setting the altitude 500 feet above the landing altitude for the entire flight and letting the outflow valve maintain the cabin pressure appropriate to the max diff. I see around 4.5 in normal operations so it must be a good cabin with no leaks. For flights around 15,000 that offers an easy way to do it, but are there any problems I have not considered?
Another consideration is the wear and tear on the airplane and it might be better to fly for minimum differential. Setting an altitude of, say, 24,000 feet would give, at maximum diff, a cabin altitude of 10,000 feet.
But I am not able to determine the pressurization schedule. Does the system go to maximum diff (or to the highest value needed for the cruise altitude selected) or is it proportional to the cruise altitude and actual altitude being flown? For example, if I set the cruise altitude to sea level and flew at around 1000 feet, would the cabin go to an altitude below sea level?
Is it always trying to go to max diff or is it more intelligent than that?