What is the maximum cabin pressure differential (PSID) for normal operations?

• A. 5.00 PSID
• B. 5.25 PSID
• C. 5.75 PSID
• D. 6.00 PSID

Answer: (C)

Cabin pressurization is limited by how much structural stress the fuselage can safely handle from inside to outside air pressure. The PC-12 NGX is designed to maintain a maximum cabin differential of 5.75 PSID during normal operations, with a relief mechanism in place to prevent over-pressurization if pressure trends toward higher values. This limit balances keeping the cabin comfortable (at the chosen cabin altitude) with protecting the airframe from excessive load. The other numbers would either constrain the cabin pressure too much or exceed the normal-operating limit, which is why 5.75 PSID is the correct specification.