2 tables appear under this heading.
1. PDF page 405
| C-5 | KC-10 | KC-135, E-3 | C-17 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Hz | g²/Hz | dB/Oct | Hz | g²/Hz | dB/Oct | Hz | g²/Hz | dB/Oct | Hz | g²/Hz | dB/Oct |
| 15 | 0.003 | 15 | 0.0038 | 10 | 0.002 | 5 | 0.005 | ||||
| 1000 | 0.003 | -6 | 1000 | 0.0038 | -6 | 67 | 0.002 | 6 | 67 | 0.005 | 6 |
| 2000 | 7.5E-4 | 2000 | 9.5E-4 | 150 | 0.01 | 150 | 0.025 | ||||
| rms = 2.11 g | rms = 2.38 g | 500 | 0.01 | -6 | 500 | 0.025 | -6 | ||||
| 2000 | 6.3E-4 | 2000 | 1.6E-3 | ||||||||
| rms = 2.80 g | rms = 4.43 g | ||||||||||
| T-43A (737) | General Exposure | Note: C-17 levels apply to the primary cargo floor. Levels for items carried on the aft ramp are higher. | |||||||||
| Hz | g²/Hz | dB/Oct | Hz | g²/Hz | dB/Oct | ||||||
| 10 | 0.015 | 15 | 0.01 | ||||||||
| 20 | 0.015 | -9 | 106 | 0.01 | 6 | ||||||
| 34 | 0.003 | 150 | 0.02 | ||||||||
| 47 | 0.003 | 9 | 500 | 0.02 | -6 | ||||||
| 80 | 0.015 | 2000 | 1.3E-3 | ||||||||
| 500 | 0.015 | -6 | rms = 4.02 g | ||||||||
| 2000 | 9.5E-4 | ||||||||||
| rms = 3.54 g | |||||||||||
2. PDF page 407
| W0 = WA + Σ1n(WJ) | |
|---|---|
| W0, WA, WJ - Exposure levels in acceleration spectral density (g²/Hz). | |
| Aerodynamically induced vibration | |
| WA = a × b × c × (q)² | |
| Jet engine noise induced vibration | |
| WJ = {[0.48 × a × d × cos²(θ)/R] × [Dc × (Vc / Vr)³ + Df × (Vf / Vr)³]} | |
| a - Platform / Materiel interaction factor (see Annex A, paragraph 2.4). Note that this factor applies to W0 and not to the low frequency portion (15 Hz to break) of Figure 514.8C-10. | |
| = 1. 0 for materiel mounted on vibration isolators (shock mounts) and materiel weighing less than 36.3 kg. | |
| = 1.0 ×10(0.6 - W / 60) for materiel weighing between 36.3 and 72.6 kg.(w = weight in kg) | |
| = 0. 25 for materiel weighing 72.6 kg or more. | |
| b - Proportionality factor between vibration level and dynamic pressure (SI units). | Σ1n - Jet noise contribution is the sum of the WJ values for each engine. |
| = 2.96 ×10-6 for materiel mounted on cockpit instrument panels. | d - Afterburner factor. = 1. 0 for conditions where afterburner is not used or is not present. = 4. 0 for conditions where afterburner is used. |
| = 1.17 ×10-5 for cockpit materiel and materiel in compartments adjacent to external surfaces that are smooth and free from discontinuities. | R - Vector distance from center of engine exhaust plane to materiel center of gravity, m (ft). |
| = 6.11 ×10-5 for materiel in compartments adjacent to or immediately aft of external surface discontinuities (cavities, chines, blade antennae, speed brakes, etc.), fuselage aft of wing trailing edge, wing, empennage, and pylons. | θ - Angle between R vector and engine exhaust vector (aft along engine exhaust centerline), degrees For 70°< θ ≤ 180° use 70°. |
| c = Mach number correction. Note that this factor applies to W0 and not to the low frequency portion (15 Hz to varc or varo) of Figure 514.8C-10. | Dc - Engine core exhaust diameter, m (ft). |
| = 1. 0 for 0 ≤ Mach ≤ 0. 9 | Df - Engine fan exhaust diameter, m (ft). |
| = (-4.8M + 5.32) for 0.9 ≤ Mach ≤1. 0 (where M = Mach number) | Vr - Reference exhaust velocity, m/sec (ft/sec). = 564 m/sec |
| = 0.52 for Mach number greater than 1.0 | Vc - Engine core exhaust velocity (without afterburner), m/sec (ft/sec). |
| q - Flight dynamic pressure, kN / m² (lb/ft²). | Vf - Engine fan exhaust velocity (without afterburner), m/sec (ft/sec). |
| varc - intersection frequency for cockpit materiel based on 4dB/oct slope from W0 | |
| varo - intersection frequency for all other materiel based on 4dB/oct slope from W0 | |
| (See Annex A, para. 2.6.1 and Table 514.8D-V) | |
| If Dimensions are in feet and pounds then: | |
| a = 1. 0 for materiel mounted on vibration isolators (shock mounts) and materiel weighing less than 80 lb. | |
| = 1.0 ×10(0.60 - 0.0075 W) for materiel weighing between 80 and 160 lb. | |
| = 0. 25 for materiel weighing 160 lb. or more. | |
| b = 6.78 ×10-9, 2.70 ×10-8, or 1.40 ×10-7 in the order listed above. | |
| Vr = 1850 feet/second | |