What is the reading on the vacuum gauge at the 35K mark?

The reading on the vacuum gauge at the 35K mark is 3.0 PSI. This value is significant because it falls within the normal operating parameters for the vacuum system of the King Air 350, ensuring that the system has adequate suction for proper instrument and equipment function. Maintaining appropriate vacuum pressure is critical for the reliability of flight instruments, such as attitude and heading indicators, which rely on that vacuum source for accurate readings. This means that a reading of 3.0 PSI indicates the system is functioning optimally at that altitude or condition, avoiding potential performance issues that may arise with pressure deviations.