SANAC Issue Paper #18

ISSUE:  Review federal guidelines on noise abatement.

BACKGROUND:  At the May 12, 1998 SANAC meeting this issue was one of thirty-eight issues brought forward as a noise reduction idea by members of the public.

ANALYSIS/DISCUSSION:  There are three federal guidelines used in aircraft noise.

The first is the measurement of noise and what is considered a noise impacted area.  Noise is measured in logarithmic units of A weighted decibels (dB or dBA).  Further consideration is given to whether this noise takes place during the daytime or at night (noise at night is more annoying because the surrounding area is quieter).  Each noise event at night is considered as being 10 times greater than the same noise during the day.  The unit of measure for this noise level is DNL.  FAA considers any area that is 65 DNL or less not to be noise impacted. FAA also makes funding available to help those living in areas with noise levels higher than 65 DNL.

The second guideline deals with engine types.  There were three types of aircraft engines; Stage I, Stage II, and Stage III.  Stage I were the noisiest and can no longer be used.  Stage II, the second noisiest, are being phased out, with December 31, 1999 scheduled to be the last day they can fly.  All air carrier aircraft after that date must be Stage III compliant.

A third guideline deals with the impact of takeoffs on the surrounding community.  In order to standardize all airports in the country, the federal government, under their National Noise Policy, has established two takeoff patterns that can be used; one to lessen noise on communities that are close is and the second to help communities that are further out.  Each airport may select which of the two patterns they prefer.

CONCLUSION:  SANAC should work toward the timely placement of noise monitors to measure community noise and the inclusion of this data in our comprehensive FAR Part 150 noise study.  With this information we should develop a federally funded mitigation plan to achieve the most good for the most people.

RECOMMENDATION:  Proceed with the study and report results. Other problems associated with adverse noise should be resolved at this level with the assistance and direction of the airport authority and the communities involved.

SUB COMMITTEE MEMBERS:  Wes Pennington, Jack Dow and Don Land.

DATE PREPARED:  September 1, 1998