What measures are used in noise abatement?

• A. Flight procedures for noise reduction.
• B. Measures to reduce noise impacts including flight procedures, curfews, and land-use planning.
• C. Increased engine maintenance schedules.
• D. Noise abatement measures include flight procedures, curfews, and land-use planning.

Answer: (D)

Noise abatement involves a set of strategies to lessen aircraft noise impacts on surrounding communities. The standard components are adjusting flight procedures to reduce noise exposure, imposing curfews to limit operations during night hours, and planning land use to shield or separate sensitive areas from noise. This makes the option that names flight procedures, curfews, and land-use planning the best answer, as it clearly and precisely lists the typical measures used. The other choices are either too narrow (focusing only on flight procedures), unrelated (engine maintenance schedules don’t directly reduce noise), or less precise in terminology (phrasing about measures to reduce noise impacts lacks the specific term and components used in noise abatement).