For the purpose of this chapter, certain words are defined as follows:
1. Air Installation Compatible Use Zone Report.
A report prepared by the Department of the Air Force examining, evaluating, and summarizing the aircraft operations at U.S. Air Force Bases with respect to the effects of noise and accident hazards.
2. Airport District One (AD I).
The area within a 3,000 by 5,000 foot rectangle having 2 of its sides parallel with, and 1,500 feet from either side of, an extension of the centerline of a runway running from 3,000 to 8,000 feet from the midpoint of the end of the runway.
3. Airport District Two (AD II).
The area within a 3,000 by 7,000 foot rectangle having 2 of its sides parallel with, and 1,500 feet from either side of, an extension of the centerline of a runway running from 8,000 to 15,000 feet from the midpoint at the end of the runway.
4. Airport District Three (AD III).
The area between the 75 Ldn and 80 Ldn noise contour lines developed by the application of the day-night average sound level methodology of sound measurement (Ldn) but not within any other airport District as defined herein.
5. Airport District Four (AD IV).
The area between the 70 Ldn and 75 Ldn noise contour lines developed by the application and the day-night average sound level methodology of sound measurement (Ldn), but not within any other Airport District as defined herein.
6. Airport District Five (AD V).
The area between the 65 Ldn and 70 Ldn noise contour lines developed by the application of the day-night average sound level methodology of the sound measurement (Ldn), but not within any other Airport District as defined herein.
7. Clear Zone.
The area within a 3,000 by 3,000 foot square having 2 of its sides parallel with and 1,500 feet from either side of, an extension of the centerline of a runway running 3,000 feet from the midpoint of the end of the runway.
8. Day-night Sound Level (Ldn).
The sound level during a 24 hour time period with a 10 decibel penalty applied to the equivalent sound level during nighttime hours of 10:00 P.M. to 7:00 A.M.
9. Decibel.
The physical unit commonly used to describe noise level.
10. High Noise Levels.
Sound levels which equal or exceed that within the 65 Ldn noise contour line developed by the application of the day-night average sound level methodology of sound measurement (Ldn).
11. Human Occupancy.
Any structure having overnight or longer living accommodations or that is intended for such use.
12. Ldn.
The day-night sound level.
13. Runway.
An artificially surfaced strip of ground designed and actively used at an airport for the landing and taking off of aircraft.
14. Severe Accident Potential.
The level of crash hazard risk associated with the Clear Zone. Said risk shall be identified in the same manner as crash hazard risk is identified in United States Air Force Air Installation Compatible Use Zone Reports for military airports.
15. Significant Accident Potential.
The level of crash hazard risk associated with Airport District II. Said risk shall be identified in the same manner as crash hazard risk is identified in United States Air Force Air Installation Compatible Use Zone Reports for military airports.
16. Substantial Accident Potential.
The level of crash hazard risk associated with Airport District I. Said risk shall be identified in the same manner as crash hazard risk is identified in United States Air Force Air Installation Compatible Use Zone Reports for military airports.