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Haroon
29th May 2012, 17:17
Hi need some help regarding the following questions. Just to confirm if I am making a mistake somewhere or there is some error in the questions.

Q.1. (Refer to figures 031_L500 and 031_L502) Just prior to departure, you accept 10 passengers additional on board who will be seated in compartment OC and you have 750 kg unloaded from cargo compartment 5. The takeoff centre of gravity in MAC % (Mean Aerodynamic Chord) will be located at:

a) 27.8%
b) 30.5%
c) 28.5%
d) 23.1%

a) marked correct whereas (c) seems to be closer to the correct value. (a) is correct without applying fuel index correction, but fuel index correction needs to be applied.

http://www.theairlinepilots.com/forumarchive/mb/lrjt5.jpg

http://www.theairlinepilots.com/forumarchive/mb/lrjt6.jpg


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Q.2. (Refer to figure L_303) The weight and balance sheet is available and contrary to the forecast, cargo compartment 1 is empty The zero fuel weight centre of gravity in MAC % (Mean Aerodynamic Chord) is located at:

a) 26.8%
b) 23.5%
c) 33.9%
d) 31%

(c) marked correct whereas (a) seems to be correct

http://www.theairlinepilots.com/forumarchive/mb/cg11.jpg

http://www.theairlinepilots.com/forumarchive/mb/cg12.jpg

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Q.3. (Refer to figures 031_L500, 031_L503 and 031_L504) Knowing that:

Dry operating mass: 110000 kg
Basic index: 119.1
Number of passengers: 185
Distributed as shown in the annex (75 g per Pax)
Cargo load + luggage: 14000 kg
Distributed as shown in the annex
Fuel: 42000 kg

Stages (1) to (7) and (11) having already been calculated, the centre of gravity in % MAC (Mean Aerodynamic Chord) for zero fuel mass is located at:

a) 29.3%
b) 28.3%
c) 30.5%
d) 32.3%

(c) marked correct whereas in my workout its coming close to 28.3 i.e option (b)

Fig L500 (http://www.theairlinepilots.com/forumarchive/mb/L500.jpg)

Fig L503 (http://www.theairlinepilots.com/forumarchive/mb/L503.jpg)

Fig L504 (http://www.theairlinepilots.com/forumarchive/mb/L504.jpg)

Thanks a lot