Page 168 - Aeronautical Engineer Data Book
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Approach speed lies between 1.45 and 1.62 V stall . Approach C L lies between C Lmax /2.04 and C Lmax /2.72. C L generally lies between 0.44 and 0.5. Long range aircraft engines are size
Some ‘rules of thumb’ climb’ requirements. 1.7 < C Lmax < 2.2 1.18 < C LV 2 < 1.53 17 < L/D < 21 O < 0.57 M E 0.46 < O M T M
W/S = 0.5 V 2 C L in the ‘approach’ condition. where q = 0.5 V 2 R A wb . 1 Gust response parameter = W S) / ( 1wb is the wing body lift curve slope obtained
Basic relationships 0.98(W/S) C L = q data sheets. s = kM 2 g 2 /(S w T.C LV2 ) existing aircraft data. M TO = M E + M PAY + M f
Table 9.3 The ‘first approximations’ methodology
Estimated parameter 1. Estimate the wing loading W/S. 2. Check C L in the cruise. 3. Check gust response at cruise speed. 4. Estimate size. 5. Estimate take-off wing loading and T
