What condition must be met for the pneumatic canopy pressure seal to inflate?

The correct answer is that the pneumatic canopy pressure seal inflates when the weight is off the right main landing gear. This condition is specifically designed to ensure that the pneumatic pressure system engages properly, allowing the canopy to create a sealed environment for the cockpit.

When the weight is off the right main landing gear, it indicates that the aircraft is in a suitable position, such as being airborne or during a specific ground operation prior to takeoff. The pneumatic system relies on this condition to activate and ensure a proper seal is formed, which is essential for maintaining cabin pressurization, especially during flight operations.

In this context, the actuation of the pneumatic canopy pressure seal could be compromised if weight is still on that landing gear, meaning the necessary mechanical and electrical signals to initiate the inflation process are not met. The other options imply a weight condition that would not trigger the necessary systems to inflate the seal appropriately.