Question

practice weight and balance quiz: question 50 of 55
an aircraft with an empty weight of 2,100 pounds and an empty weight cg +32.5 was
altered as follows:

1. two 18 - pound passenger seats located at +73 were removed;
2. structural modifications were made at +77 increasing weight by 17 pounds;
3. a seat and safety belt weighing 25 pounds were installed at +74.5; and
4. radio equipment weighing 35 pounds was installed at +95.

a +34.01.
b +33.68.
c +34.65.

Explanation:

Step1: Calculate the total weight change

• Original empty weight \(W_0 = 2100\) pounds.
• Weight removed: \(2\times18=36\) pounds.
• Weight added due to structural modification: \(17\) pounds.
• Weight added for seat and safety belt: \(25\) pounds.
• Weight added for radio equipment: \(35\) pounds.
• New weight \(W=(2100 - 36+17 + 25+35)=2141\) pounds.

Step2: Calculate the total moment change

• Original moment \(M_0=2100\times32.5 = 68250\)
• Moment removed: \(36\times73=2628\)
• Moment added due to structural modification: \(17\times77 = 1309\)
• Moment added for seat and safety belt: \(25\times74.5=1862.5\)
• Moment added for radio equipment: \(35\times95 = 3325\)
• New moment \(M=(68250-2628 + 1309+1862.5+3325)=72118.5\)

Step3: Calculate the new CG

• New CG \(=\frac{M}{W}=\frac{72118.5}{2141}\approx33.68\)

Answer:

B. +33.68