Systems Group Mass
MTOW = 9,500kg (use Equation 8.47),MsYs = 0.11 x 9,500 = 1,045 kg.
8.11.5 Furnishing Group Mass
MTOW = 9,500 kg (use Equation 8.50), Mfur 0.065 x 9,500 = 618 kg
8.11.6 Contingency Group Mass
MTOW = 9,500kg (use Equation 8.52), MCoNT = 0.015 x 9,500 = 143 kg
8.11.7 Crew Mass
There are two flight crew members and no cabin crew. Therefore, Mcrew = 2 x 90 = 180 kg.
8.11.8 Payload Mass
There are ten passengers. Therefore, Mpl = 10 x 90 = 900 kg.
8.11.9 Fuel Mass
The range requirement is 2,000 nm carrying ten passengers. From statistical data given in Table 8.1, take the highest value of 26% of MTOW, Mfuel = 0.26 x 9,500 = 2,470 « 2,500 kg.
8.11.10 Weight Summary
Table 8.5 is the weight summary obtained by using the coursework example worked out thus far. The last column provides the estimation as a result of the graphical solution (in bracket – kg).
This computation requires further iterations to be fine-tuned for better accuracy. The CG position is established in the next section, when further iterations will yield a better picture.
Variant Aircraft in the Family
For simplification, linear variations are considered, which should be worked out as a coursework exercise.
Table 8.6. Typical values of component CG locations: civil aircraft
Longer Variant. Increase APayload = 400 kg, AFuselage = 300 kg, AFurnish = 200 kg, AFuel = 300 kg, and AOthers = 200 kg. Total increase = +1,400 kg; MTOMLong = 10,900 kg (no structural changes).
Smaller Variant. Decrease APayload = 500 kg, AFuselage = 350 kg, AFurnish = 250 kg, AFuel = 350 kg, and AOthers = 250 kg (lightening of the structures). Total decrease = -1,700 kg; MTOMSmall = 7,800 kg.