Which of the following procedures may help control noise from aircraft?

The correct answer focuses on the implementation of preferred runways and minimum noise routes, which is an effective strategy for managing and controlling noise produced by aircraft during takeoff and landing. Preferred runways are those designated for use under certain wind and weather conditions that can help minimize noise impact on populated areas.

Minimum noise routes are specific flight paths that aircraft are encouraged to follow in order to avoid densely populated areas, reducing the exposure of sensitive communities to noise pollution. By guiding aircraft along these paths, the overall noise footprint can be effectively minimized, thus enhancing the quality of life for those residing near airports.

Increasing flight altitudes may seem beneficial at first, as higher altitude flights could potentially reduce noise levels; however, it is not always feasible or practical for all flying operations, especially during takeoff and landing phases. Shorter flight paths may not necessarily lead to reduced noise levels and could also contribute to increased traffic congestion near airports. Reducing takeoff weights can indeed reduce noise; however, it is not a direct procedural control like the implementation of preferred runways and noise routes, and it might not always be the safest or most efficient option for flight operations.