21B Pressurization
TTP B1-L3 ATA 21B Beech 90 Series B2-L3 Pressurization Pressurization , with a maximum pressurization differential of 5.0 psi d , is r e gulated through a pressurization controller and a s witch on the pedestal. The CABIN A L T knob of the controller is used to select the desired cabin pressure altitude on the controller dial, w hile the controller R A TE knob r e gulates the cabin rate of climb and descent. During no r mal operations, the cabin controller positions the outfl o w v al v e on the rear pressure b ulkhead. A safety v al v e, inboard of the outfl o w v al v e, protects the pressure v essel from o v e r pressurization w hen airbo r ne and pr e v ents pressurization on the g round. A cabin rate-of-climb g auge and a coaxial g auge, sh o wing cabin pressure altitude and cabin psi d , are on the conso...