Cabin Pressure and Bypass Ratios
"skippy" was flying along in a T-19 near the operational vertical limit (service ceiling) and got distracted. He unknowningly continued to climb and suddely, without warning, the pressure vessel popped. His death was surely painless.
Many of our technologies and most of our regulations stemmed from disasters like these.
We initially reported some deficiencies in this area of cabin pressure and pressure regulation and CAS messaging back in 2020 but
hadn't sat down to fully flesh out the implications of operating on the surface at 2.5+ bar and going to orbit and back while maintaining passenger comfort.
Ultimately we decided on some pretty substantial engineering to allow 2+ bar pressure differentials. The orbiting space stations are at 1 bar. Ground dwellers who venture out of their habitats would experience high Nitrogen levels at 2.5 bar. We imagine they wouldn't build the structures to sustain a pressure differential but would enjoy more normal partial pressure of Nitrogen by substituting other inert gases. Those that have to work outside would be called "Narcs" because of the subtle but real threat of Nitogen Narcosis at that pressure.
If surface destination set it will gradually (500 fpm for comfort) adjust the cabin pressure to meet the destination.
If they have no destination and are below 10km it will use radar altimeter to determine a touchdown elevation and equivalent ISA pressure.
If they are above 10km or have a non-surface destination then it will use 1 bar.
Oh and while we were in there we added the bypass ratios to the engine definitions for every vehicle type!
Many of our technologies and most of our regulations stemmed from disasters like these.
We initially reported some deficiencies in this area of cabin pressure and pressure regulation and CAS messaging back in 2020 but
hadn't sat down to fully flesh out the implications of operating on the surface at 2.5+ bar and going to orbit and back while maintaining passenger comfort.
Ultimately we decided on some pretty substantial engineering to allow 2+ bar pressure differentials. The orbiting space stations are at 1 bar. Ground dwellers who venture out of their habitats would experience high Nitrogen levels at 2.5 bar. We imagine they wouldn't build the structures to sustain a pressure differential but would enjoy more normal partial pressure of Nitrogen by substituting other inert gases. Those that have to work outside would be called "Narcs" because of the subtle but real threat of Nitogen Narcosis at that pressure.
If surface destination set it will gradually (500 fpm for comfort) adjust the cabin pressure to meet the destination.
If they have no destination and are below 10km it will use radar altimeter to determine a touchdown elevation and equivalent ISA pressure.
If they are above 10km or have a non-surface destination then it will use 1 bar.
Oh and while we were in there we added the bypass ratios to the engine definitions for every vehicle type!