The system used in large aircraft to prevent over stressing of the trailing edge flaps is the:

• A. Flap load relief system
• B. Flap bypass system
• C. Leading edge slat limiter
• D. Flap drive limiter

Answer: (A)

The system in question is designed to protect the trailing edge flaps from structural overstress by automatically reducing the load on them whenever loads become too high. It works by monitoring flap loads and, if they approach a preset limit (such as during strong gusts or aggressive maneuvers), it relieves hydraulic pressure to the flap actuators or otherwise unloads the flap mechanism. This keeps the flaps within safe load limits without requiring immediate pilot input, helping prevent bending moments or fatigue that could damage the flap system. The flaps may flatten their load on the wing rather than forcing more force into the actuators, allowing continued safe operation.

Flap bypass systems are intended to route the hydraulic or control pathways around certain components, not primarily to limit flap loads. Leading edge slat limiters control the deployment of slats on the wing’s leading edge, which is a different part of the high-lift system. A flap drive limiter would constrain the actuator movement rate or travel, but the specific protection of trailing edge flap structures from overstress is the job of the flap load relief system.