Commercial Pilot License (CPL) Practice Exam 2026 - Free Commercial Pilot License Practice Questions and Study Guide

The cabin differential pressure gauge serves a crucial function in monitoring the pressure difference between the cabin and the outside environment. This difference is essential for maintaining a safe and comfortable atmosphere for passengers, especially at high altitudes where external air pressure drops significantly. The gauge provides pilots with vital data to assess whether the cabin is being pressurized correctly and to detect any potential leaks or malfunctions in the pressurization system. By keeping within designated pressure limits, the safety and comfort of those on board are ensured, preventing issues such as hypoxia or structural stress on the aircraft.

Other options, while related to flight safety or operation, do not accurately describe the function of the cabin differential pressure gauge. Fuel level indication is related to fuel management, cabin noise monitoring pertains to passenger comfort, and regulating oxygen levels is typically managed through separate systems, not directly indicated by the differential pressure gauge.