What is the maximum permissible differential pressure at an aircraft pressure altitude of 18,069 ft?

To determine the maximum permissible differential pressure at an aircraft pressure altitude of 18,069 feet, one must consider the guidelines set by aviation regulatory bodies and the engineering specifics related to aircraft cabin pressure systems. At this altitude, the allowable differential pressure is affected by factors such as structural integrity, safety, and cabin pressurization laws.

The correct answer reflects the standard maximum differential pressure specified for that altitude, which is typically set to ensure that the aircraft's fuselage can safely withstand the stresses of pressurization, while also providing a safe environment for the occupants. It is established through certification data and operational safety practices. In this case, 3.6 +/- 0.2 is aligned with accepted safety measures for commercial aircraft at that altitude.

The other options, despite being valid numbers, do not fall within the established parameters for maximum differential pressure at 18,069 feet. Each figure represents a different potential performance value, but 3.6 +/- 0.2 is particularly chosen based on the industry standards that apply to the altitude in question.