Explanation: The diagram is representing altitude vs time relation. It is also called ‘mission profile’ of an aircraft. This mission profile consist only basic phases of flight. Hence, it can be termed as simple cruise mission profile.

Explanation: For any mission leg or mission phase, mission fuel fraction is ratio of fuel weight at the end and at beginning of each phase. Hence, if it is mission phase n then, (n-1) will be the phase before nth phase. Hence, correct answer is Wn / Wn-1.

Explanation: Lofting is a vital part of preliminary design phase. The fuel fraction method is very simple and basic approximation method. Here, mission profile is divided and then for every individual phase we calculate mission segment weight fraction.

Hence, fuel consumed during this mission = Wf = W0 * 0.015 = 10000 * 0.015 = 150lb.

Explanation: Breguet endurance formula is used to determine the endurance of aircraft. Range formula is used to calculate range for respective mission. In simple sizing method we consider that the cruise is ending with descent. Also, we assume that cruise range has accounted for descent as well. Hence, we use range formula to determine fuel fraction.

Wn/Wn-1 = \(e^{\left(-\frac{R*C}{V*\frac{L}{D}}\right)}\)

Since, reserved fuel is not mentioned we can neglect it.

Explanation: We can divide whole mission profile of aircraft into number of mission phases or legs. Fuel fraction at each mission segment will be fuel weight at end of phase to that of beginning. Hence, if there are z – number of mission phase then, final mission phase fraction will be multiplication of individual weight fraction which will give weight fraction w.r.t. take-off gross weight W0

Explanation: Climb phase usually measured by rate of climb. Climb endurance formula is used to determine the endurance of aircraft at climb phase. Typically we can find climb weight fraction from historic time line however in some cases we can also use climb endurance formula to determine fuel fraction.

Now if we double the value of aerodynamic efficiency the denominator will increase which in turn increases fuel fraction during cruise.

Explanation: Fuel conception or fuel fraction during cruise segment will be affected by the overall aerodynamic efficiency. The aerodynamic efficiency is ratio of lift and drag. Lift is directly affected by the wetted area, which affects L/D. As a result, it will affect fuel fraction during cruise mission phase.

Wcruise / W0 = \(e^{\left(-\frac{R*C}{\eta*\frac{L}{D}}\right)}\) = \(e^{-(\frac{7 * 10^ 6* 1.38 * 10^ {-7}}{0.9*14})}\) = 0.9261.