Username Protected wrote:
John, it sounds like the Lear was equivalently pressurized to the U2 if you were are 10,000 PA at 51,000 and the U2 is at 29,000 feet at 70,000? I wonder what it would take in terms of fuselage strength to build a plane that had a 10k PA at 70,000?
Off the top of my head, the single-seat U-2's were pressurized at a 3.8 psi differential... which gave the 29,000' cockpit altitude at FL700. The two-seaters still have that pressurization schedule, since they were unmodified.
All single-seaters (except for NASA's two jets) were modified to a 7.6 psi differential... cutting cabin altitude to ~14,500' at FL700. The decompression sickness issues that have plagued the U-2 community for so long should be a thing of the past.
Two unplanned consequences of the modification are that O2 consumption increased, and the cabin cooling is not near what it used to be.