18 / 20

Calculate the aircraft’s CG position given the following weighing data.

Mass on nose wheel: 285 kg
Mass on left main wheels: 1465 kg
Mass on right main wheels: 1395 kg
Distance between the nose and main wheels: 7 ft 8 in

• A
7.1 ft aft of the nose wheel.
• B
83.7 in aft of the nose wheel.
• C
18.3 in forward of the main gear.
• D
9.2 in forward of the main gear.
Remember for all CG calculations to use the equation below:
New mass x New CG = (Old mass x Old CG) ± (mass x arm)

Total main wheels mass (left and right) = 1465 + 1395 = 2860 kg
We need to assume that the old mass of the airplane is the mass of the main wheels only and the new mass will include the nose wheel considering nose wheel arm as negative arm as its in front of the main wheels.
New mass = 2860 +285 = 3145 kg

Nose wheel in front of main wheel ( 7 ft and 8 inches)
1 feet = 12 inch
Nose wheel is 92 inches infant of the main wheel

3145 x New CG = (2860 x Zero) - (285 x 92)
New CG = — 26220 / 3145 = — 8.3 inches
New CG is 8.33 inches in front of the main wheel
We know that the nose wheel is 92 inches in front of the main wheel

Distance of the new CG from the nose wheel = 92 - 8.3 = 83.7

Correct Answer: 83.7 inches aft of the nose wheel.

Your Notes (not visible to others)

This question has appeared on the real examination, you can find the related countries below.

• Austro Control
• Poland
• Greece
• Iceland
• Italy
• Bulgaria
• Denmark
• Ireland
• Portugal
• United Kingdom