What are the limitations on thrust reversers during ground use?

The correct choice conveys that thrust reversers are limited to 30 seconds of continuous use when a 20-knot tailwind is present. This restriction is designed to prevent overheating and potential damage to the thrust reversers due to excessive operational time while subjected to wind conditions that could affect their efficacy. When operating under such wind conditions, the safeguards are put in place to maintain the integrity and safety of the thrust reverser system.

Thrust reversers are critical components used primarily during landing to help slow down the aircraft after touchdown. However, their performance and the effects of wind are carefully monitored to avoid incidents that could arise from prolonged use in adverse conditions. This limitation also emphasizes the need for pilots to be aware of environmental variables when deploying thrust reversers.

Other options might suggest different time limits or conditions which either do not align with safety recommendations or overlook specific operational factors like tailwind that significantly influence thrust reverser effectiveness. Thus, the correct understanding of the limitation on ground use with regard to thrust reversers is captured effectively in that accurate option.