How many multifunctional spoilers are operational after a hydraulic failure?

The correct answer is based on the functional design and redundancy of the aircraft's hydraulic systems and the spoiler mechanisms. In the event of a hydraulic failure, the operation of the spoilers is affected selectively depending on their location and the hydraulic systems that control them.

Multifunctional spoilers on an aircraft are typically divided into inboard and outboard sections, each controlled by separate hydraulic systems. In most designs, if one hydraulic system fails, the outboard spoilers, which are primarily used for lift and roll control, become inoperative due to their dependency on the failed hydraulic source. This means that while the inboard spoilers may still function using an alternative hydraulic source or backup system, the outboard flight spoilers are rendered non-operational.

This characteristic allows the aircraft to maintain some level of control using the functional inboard spoilers, which can still assist during critical phases of flight, such as landing or maneuvering, despite one hydraulic failure. Understanding this operational dynamic is essential for grasping how aircraft systems are designed for safety and redundancy.