What must be checked after major components are installed but before flight testing?

Checking the weight and balance after major components are installed is crucial before flight testing. This ensures that the aircraft is within its prescribed center of gravity limits and total weight capacity for safe operation. Any changes in the aircraft configuration, such as alterations in components or equipment, can significantly impact the overall weight distribution and balance. If the weight and balance are not within acceptable limits, it can lead to poor flight characteristics, compromised control, and potentially hazardous flight conditions.

In this context, ensuring that the aircraft is balanced not only affects flight stability and maneuverability but also adheres to regulatory requirements, promoting safety in the testing phase. Addressing this aspect before the aircraft is flown is an essential step in the pre-flight checklist, ultimately contributing to the reliability and safety of the flight test phase.