MODEL ‘INVALIDATION’ ?

1. MODEL ‘INVALIDATION’ ? Examination of noise study shows inaccurate, incomplete, and unscientific INM modeled vs. measured INM validation. Reliable INM validation is the crucial first step in using 65 dB DNL contours upon which the majority of environmental impact findings are based.

2. Questions about INM Inputs – have they been adequately addressed in one week sample of data? Inputs to INM • Airport characteristics (runways, orientation, etc.) • Approach and departure profiles – OSU Modeled vs. Actual flight profiles show modeled profiles consistently higher. • Flight tracks + Approach + Departure + Touch-and-go – Are all touch-and-go flights included in OSU noise study? Are there nighttime jet touch-and-go flights that have not been accounted for? + Circling – Has ANY attempt been made to characterize the effect of student training circling? + Overflights

3. Questions about INM Inputs – have they been adequately addressed in one week sample of data? • Flight operations + Numbers of aircraft assigned to each track + Percent aircraft assigned to each track – Noise study does not list specific aircraft types used at airport or INM substitutions made. + Runup operations – Was there any attempt to add noise due to runup operations? • Noise Metric Select among DNL, CNEL, NEF, TNEL, and 12 others -- Noise Study was run to include 55DNL contour (from OSU INM input data), but the 55DNL contour was never presented. Why? Wyle Labs ‘believes that the best metric to characterize the noise environment is the Number of Events (z) above a threshold noise level (x).’ Why did Wyle Labs not calculate this and show to the community as an important informational metric?

4. From INM input Aircraft ID used in preliminary study From INM input Aircraft ID used in final study Questions about Aircraft Type and Fleet Mix What happened to GIIB, HS748A aircraft in final study? Were they not used because they are noisy Stage 2 jet aircraft? OSU Master Plan Update shows Hawker and GII jets using airport – why are they not included in final noise study? Source – directly copied from OSU INM Input Data Disk provided by Airport

5. With a number of questions surrounding the legitimacy of INM input values, it would seem important to the authors of the noise study to alleviate concerns by doing a thorough and objective noise model validation to prove that the INM is accurately computing noise contours around OSU Airport. Noise model validation receives four lines in the main report and three pages in the appendix. More paragraphs were devoted to discussion of noise effects on caribou, bighorn sheep, wolves, and the effect of sonic booms on marine mammals such as manatee, fur seals, sea lions and ringed seals than on scientific conclusions regarding model validity.

6. Total number of measured events is 0.475% of 2003 operations Incorrect formula used for Standard Deviation of SEL of Measured Events Standard error of mean difference not calculated Arbitrary and subjective difference of 3 dB chosen for model validation NO objective, statistical test of model validity was used Based on study criteria of mean difference < 3dB with number of measured events >2, only 19.2% of measured events and 12.3% of operation types were accurately predicted by INM. Model Validation ?

7. Comparison of Measured to Modeled Noise Levels Source of chart data – OSU Noise Study

8. Flight Profiles Calculated from INM Are Consistently Higher Than Actual Flight Profiles Derived from Radar Data “The actual aircraft profiles are comparable to those in the noise model and no adjustments were made.” Source – OSU Noise Study No modeled vs. actual profiles were shown in the study and no attempt was made to scientifically correlate modeled vs. actual flight profiles. ‘Comparable’ is an arbitrary and subjective measure.

9. Top Two Utilized Jet Departure Modeled vs. Actual Profiles The INM flight profile is almost always higher - by hundreds of feet - at relevant track distances for validation < 3000ft. Source-Advisory Committee Meeting 6/23/04

10. Top Two Utilized Multi Engine Departure Modeled vs. Actual Profiles INM Flight Profiles Higher than Actual Flight Profiles Source-Advisory Committee Meeting 6/23/04

11. Misleading ‘Community Noise’ • Study continues to imply that community noise at all noise monitors is larger than aircraft noise. No attempt was made to characterize SOUNDS measured at monitors other than aircraft noise, yet a Community DNL was calculated. DNL metric is only valid for noise, since it attaches a penalty for nighttime events. From Larson Davis LD-820 sound level meter instruction manual (meter used in OSU Noise Study): • Difference between sound and noise: Use of the word sound provides a neutral description of some acoustic event. Generally, noise is defined as unwanted sound. It can also be defined as sound that causes adverse effects on people such as hearing loss or annoyance. In every case, noise involves the judgment of someone and puts noise in the realm of psychology not physics. • The descriptor should be used only when negative effects on people are known to occur. Rule: Use word sound to describe measurements to remove the emotional overtones associated with the word noise. • Study breaks rule recommended by sound level meter manufacturer by calculating Community DNL without attempting to distinguish between sound and noise events.

12. Average DNL at Measured Locations (for measurement period: 17-25 Feb. 2004) 75 Overall DNL – as measured, includes aircraft and community noise sources Aircraft DNL – only noise attributed to aircraft events 70 Community DNL – all non-aircraft noise sources Incorrect use of Community DNL as ‘noise sources’ 65 Day-Night Average Sound Level, DNL (dB) 60 55 50 45 5 6 7 8 9 10 11 12 13 14 15 Noise Monitoring Site

13. Appropriate Measure of Background Noise L90 is metric commonly employed to represent background sound level. L01 represents typical ‘noisy’ levels. This graph clearly shows difference in levels between background sound levels and noisy events such as aircraft events. Source – OSU Noise Study