Question

The lift and drag graphs of the model airplane weights.7 lbf are shown in Fig 6.1 and 62 below Figure 6.1 Lift vs angle of attack of thae jet fighter mode Figure 6.2 Dig v angle of attack of the jet fighter model 1.2 08 500 0400 06 04 02 100 024610 12 14 16 18 20 22 24 0 24610 12 14 16 18 20 22 24 a C) 20MPH Determine: Figure 63 LD i angle of attack of the jet Lighter mod (a) Airspeed (s) and AOA(s) needed for take-off 12000 เงิ 10,000 8000- (b) Minimum power required for take-off and sustain flight (c) The lit-to-drag ratio, or L/D ratio, is the amount of lift (F generated by an airplane, divided by the drag (Fp) it creates by moving through the air. A higher or more favorable L/D(or F/Fp) 2000 ratio is typically one of the major goals in aircraft design; since this0,000 particular aircrafts needed lift is set by its weight, delivering that lift with lower drag leads directly to better fuel economy and climb performance. From figure 6.3 at what angle of atack(s) and speed(s) would you recommend for the best fuel economy,if the plane has sufficient power? 0246 10 12 14 16 18 20 22 24 Pely. 0

Answer 1

al . Ai, speed (s) and noA (s) needed fa.4cdre-o66 gh Citen ed Pout re Fest she asoplace FL should be heve 21 C.

At v- 30 MPH and 12 otfelbsise. 6speed increde the AcA decneale) counte balance Fo cnc Pevide eqne lane onnina a constent speed aro Fo- 616 3660 ou in Ft sec

FD 3 125 FD 3oPth x(%) F O