What is a potential hazard of operating thrust reversers at low ground speeds?

Operating thrust reversers at low ground speeds poses a potential hazard primarily due to the ingestion of foreign object debris (FOD). When thrust reversers are deployed, they redirect engine thrust forward to slow the aircraft down. At low speeds, the aircraft is closer to the ground where there may be debris, dirt, gravel, or other objects that can be ingested by the engines. This ingestion can cause damage to the engine components such as the fan blades or other critical parts, leading to potential engine failure or the need for expensive repairs.

This concern emphasizes the importance of ensuring that the area around the aircraft is clear of debris before deploying thrust reversers, especially during taxiing and landing phases. Additionally, at low speeds, the effectiveness of the thrust reversers can be reduced, further prompting the need for caution as they may not provide adequate deceleration without risking damage from debris.

The other options, although they may have their own risks, do not directly relate to the operation of thrust reversers at low ground speeds in the same way that FOD ingestion does.