Question 1: Answer not provided Question 2: What is the basic premise behind each of the common noise compatibility measures an airport operator can pursue? Noise is measured in dB (decibel) which is unit less but is compared to pressure which is measured in Pa (N/m²). One dB is comparable to 20 micro Pa what is similar to 2 nano N/cm² whereby 1 cm² is about the area of the ear drum. The function of decibel is a logarithmic function which means that within an increase of 10 decibel, the intense gets multiplied with 10. The decibel scale is ranged from 1‐130db whereby 130 dB is the most pain full exposure to a humans ear drum and has an intense of 20000 N/cm² and 1 dB the less possible level of sound which can be listened by a human. Noise in general is a very subjective measure and is recognized by each other person different. While the one feels the sound of a Cessna like sound in the ears for others it is really disappointing. While younger people are relatively robust to high sound levels, people in their middle age and little kids feels really sensitive to higher sound levels and older people probably even didn’t hear it at all. People in cities are probably less sensitive to noise than people from outside the city since the basic noise from streets and people is always there. Nature can also make noise (rain, winds etc). Further it is remarkable, that people are always exposed to noise, there is basically no possibility of receiving an absolute quietness. All this inputs makes it really difficult to define a measurement of sound /noise around airports and requested a lot of studies, tests and statistics in past to determine what kind the noise average of people is sensible. Taking all this considerations into mind the FAA requested the following criteria for a noise measurement parameter in the environment of an airport: ‐ measurement must be taken over a one year period ‐ The measurement must be recognized by the public and taken all the considerations named above into account ‐ the noise level is predictable due to the aircraft events producing the noise According to this requirements different theories were developed for noise levels and their reading. The outcome were the following parameters most applied: DNL – Day Night level average ‐ measures in units of dB from 55 – 75 whereby 65 is the last acceptable. During night 5 dB gets automatically added from 10 pm to 7 am because of the more sensitiveness of the people to noise during the night. applied: CNEL – community noise equivalent level same like DNL but adds 5 dB from 10 pm to 12 am and 10 dB from 12am to 7 am not applied: NEF – noise exposure E:\DVDs\GG\7\RipIt4Me.psl displays the average increase of noise through air traffic in the scale of 20 dB to 40 dB increase to the basic sound level not applied: CNR ‐ composite noise rating ‐ were also not accepted by the public. It displays the whole range of dB and assumes that a average of 90 to 100 is still acceptable since people almost exposure to heavy noise while talking, cars, streets etc. . Question 3: What are the significant provisions of these federal legislative acts? FAR Part 36 ANCA ASNA FAR Part 36 established noise certification standards for the design of turbojet and transport category aircrafts. Its main purpose was to mandate changes that would reduce or eliminate noise at its source. Noise reduction under part 36 primarily focused on the modification of engine design to provide higher air bypass rations, thus reducing noise coming out of engines. ANCA is the 1990 Airport Noise Capacity Act. It put a limit on the number of stage 2 aircraft over 75,000 pounds maximum takeoff weight that were allowed to operate in the U.S. The act also stated that stage 2 aircrafts should be phased out of the U.S by December 31, 1999. (Stage 2 a/c have engines that represented newer technology than stage 1, and stage 3 have the most technologically advanced engines) ASNA is the Airport Safety and Noise Abatement act of 1979 which provided a basis for a great majority of noise reduction planning at airports. With the passage of this act congress directed the FAA to develop and establish procedures for noise and land use compatibility programs for the nation's airport Question 4: unanswered Question 5: What are the impacts and consequences of noise contours developed from noise exposure maps? Noise contours outline a band of noise created from airport operations read from NEMs or noise exposure maps. NEMs are created by a computer generated model called an INM, or an integrated noise model. The noise which noise contours are outlined from are meausred in DNL, or the Day-Night Sound Level. This is significant because it is an average of total sound over a period of time instead of pinpoint events. Noise contours diagram significant noise levels, such as the "magical" 65 DNL number. Any land outside of this 65 DNL area (65 DNL and quieter) are considered compatible for any kind of use, whether it be a park, or a school, or office building. Other contours are drawn out, such as 70, and 75 DNL (unacceptable levels), which can sometimes render the land incompatible for development into schools or office buildings. For reference as to what 65 DNL sounds like, 60 DNL is an average urban residential environment with no special disturbances. Some impacts that these noise exposure maps have on the community are that everything within the 65 DNL and up contour, the airport has to "noise treat", or "sound insulate" down to an interior level of at least 50 DNL. There are many different techniques as to do this: Insulated windows, chimney baffles, landscaping, ANC (active noise control), etc. The design goal when insulating a house are to reduce sound by 30-35 decibels. If a single house on the block is treated, the rest of the block has to receive the same insulation. Reid Hillview has only four houses to insulate. San Jose International on the other hand has upwards of 2000 homes to treat. Once the NEM is approved by the FAA, homes within this 65 DNL level cannot sue for noise damages given thatthey are properly treated. With that said, noise contours help the airport be a better neighbor by taking responsibility for the noise it imposes on the community. Question 6: What is the purpose of a Part 150 noise compatibility plan? What are the components of the plan? (Answers may be found on pages 15-19) History of Part 150