Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
40 Air Operations Area (AOA) Portions of the airport designed and used for landing, taking off, or surface maneuvering of aircraft. Typically used as a security term within the secured fenced area of an airport. Crop Cover Vegetation planted to cover the soil rather than for the purpose of being harvested. Cover crops manage soil erosion, soil fertility, soil quality, weeds, pests, diseases, biodiversity, and wildlife in an agroecosystem. Examples include annual ryegrass, crimson clover, oats, cereal rye. Crop Residue Materials left in an agricultural field after the crop has been har- vested. Examples include corn stalks, stems, leaves, and seed pods. The residue can be plowed directly into the ground or burned. No-Till Farm Practice Also known as zero tillage or direct drilling, a technique for growing crops without disturbing the soil through tilling. No-till farming decreases the amount of soil erosion that tilling may cause in certain soils, especially sandy or dry soils on sloping terrains. Object-Free Area (OFA) A surface area based on the runway, taxiway, or taxilane center- line that enhances the safety of aircraft. The OFA must be free of objects, except for those items needed for air navigation or aircraft ground maneuvering (e.g., antennas, lights, signs). Riparian Filter Strip An area of vegetation typically placed between a field and a water- shed with the purpose of removing or filtering contaminants prior to entering the water. Runway Protection Zone (RPZ) A trapezoidal-shaped area located off the runway ends, designed to enhance safety. The RPZ begins 200Â ft. from the end of a runway and can vary in length from 1,000Â ft. to 2,500Â ft. Clearing all objects from the RPZ is desirable to maintain safety. Runway Safety Area (RSA) The ground area surrounding a runway maintained for reducing the risk of damage to aircraft in the event of an unintentional departure from the pavement. The RSA is maintained clear of objects unless required for aircraft navigation. RSA width may range from 120 to 500Â ft. and is typically 1,000Â ft. from the runway ends. Glossary