15 5 degrees c hai light horizontal distance to the

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15 5 Degrees (c) HAI-Light Horizontal distance to the helipad (ft) Figure 17. Sample plots of TPP angle-of-attack, steady-state and effective flightpath angles vs, horizontal distance to the helipad. (a) Quiet, (b) HAI-Medium, (c) HAI-Light.
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30 0 20 40 60 80 100 120 -3 -2 -1 0 1 -3 -2 -1 0 1 -3 -2 -1 0 1 (c) HAI-Light (b) HAI-Medium (a) Quiet Airspeed (knots) Hdot (fpm) Hdot.EFF (fpm) Hdot (fpm); Hdot.EFF (fpm) (K) Hdot (fpm); Hdot.EFF (fpm) (K) Hdot (fpm); Hdot.EFF (fpm) (K) Figure 18. Quasi-steady and effective rate of descent vs. airspeed plots for sample runs of (a) Quiet, (b) HAI-Medium, (c)HAI-Light.
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31 Starboard Mic Centerline Mic Port Mic Starboard Mic Centerline Mic Port Mic Group D Group E A-OASPL (dB) A-OASPL (dB) -15,000 -10,000 -5,000 5,000 0 -15,000 -10,000 -5,000 Horizontal distance from Mics (ft) Horizontal distance from Mics (ft) 5,000 0 A-OASPL (dB) Channel 1 Channel 2 Channel 4 Channel 1 Channel 2 Channel 4 10 dB Groups D (6 deg deceleration) and E (9 deg deceleration) Figure 19. dBA vs. horizontal distance-to-the-center mics plots (all plots with the same scale).
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32 Starboard Mic Centerline Mic Port Mic Starboard Mic Centerline Mic Port Mic Group F Group H A-OASPL (dB) A-OASPL (dB) -15,000 -10,000 -5,000 5,000 0 -15,000 -10,000 -5,000 Horizontal distance from Mics (ft) Horizontal distance from Mics (ft) 5,000 0 A-OASPL (dB) Channel 1 Channel 2 Channel 4 Channel 1 Channel 2 Channel 4 10 dB Groups F (Quiet) and H (HAI-Light) Figure 19. Concluded.
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33 3 dB Centerline Mic Starboard Mic Port Mic 6dg 80kt 400 ft 6dg decel 400 ft 9dg decel 400 ft Quiet HAI Med HAI Light C D E F G H Figure 20. dBAmax comparsion for groups C (6 deg @ 80kts), D (6 deg deceleration), E (9 deg deceleration), F(Quiet), G (HAI-Medium), and H (HAI-Light) at the three mic locations. (Note: The baselines and the scales are the same.) 3 dB Centerline Mic Starboard Mic Port Mic 6dg 80kt 400 ft 6dg decel 400 ft 9dg decel 400 ft Quiet HAI Med HAI Light C D E F G H Figure 21. SEL dB comparison for groups C (6 deg @ 80kts), D (6 deg deceleration), E (9 deg deceleration), F(Quiet), G (HAI-Medium), and H (HAI-Light) at the three mic locations. (Note: The baselines are and the scales are the same.)
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34 SEL statistics Centerline Mic Maximum dBA statistics A B C D E F G H 5 dB Figure 22. SEL dB and dBAmax statistics for all the groups tested at the centerline mic #2. (Note: The baselines and the scales are the same.) Open circles are for the mean, horizontal bars for the standard deviation, and diamonds for the range. 10 9 9 5 8 8 7 6 4 5 1 2 3 1 10 6 7 300 600 900 1200 1500 1800 2100 2400 0 10 20 30 40 50 60 70 80 90 100 110 120 3 ° 6 ° 9 ° 12 ° 130 Airspeed (knots) Glideslope Noise scale: (least to most noisy) Quiet HAI-M HAI-L Rate of descent (fpm) decel effect Figure 23. Tested noise-abatement flight profiles shown in the plane of airspeed vs. rate of descent, with and without considerations of deceleration effect.
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35 500 0 -500 -1000 20 Airspeed (knots) 40 60 80 100 120 140 0 Flare and landing Optional conversions to approach glide slope Approach Preferred path R/C BVI intensive region R/D fpm Figure 24. Preferred flightpath to avoid BVI intensive region.
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REPORT DOCUMENTATION PAGE 8. PERFORMING ORGANIZATION REPORT NUMBER 10. SPONSORING/MONITORING AGENCY REPORT NUMBER Form Approved OMB No. 0704-0188 12b. DISTRIBUTION CODE 12a.
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  • Spring '10
  • frando
  • Aerodynamics, Aviation terminology, BVI, Instrument approach, Helicopter rotor, acoustic data

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