What is the maximum ambient pressure allowed for inflight operation?

The maximum ambient pressure allowed for inflight operation is 8.5 inches of mercury (inHg). This limit is crucial to ensure the safe operation of the aircraft under various atmospheric conditions. At pressures above this threshold, performance parameters such as engine operation, pressurization, and aerodynamic characteristics may not be within their designed operational limits.

In the context of aircraft operation, it is essential to understand how ambient pressure affects the performance capabilities of the ERJ 170/175. The aircraft is engineered to function optimally within specific pressure ranges. Exceeding the maximum ambient pressure could lead to issues such as reduced engine efficiency, improper pressurization system functioning, and compromised aerodynamic stability, which can all affect safety and performance during flight.

Understanding these limitations helps pilots and operators ensure that the aircraft remains within operational safety margins throughout its flight, particularly when facing variable atmospheric conditions or during cross-country travel where elevations and weather can shift drastically.