ACS Weight & Balance 3

Question 1

An aircraft weighs 3,200 lb with a CG at 95.0 inches. A 50 lb item is removed from a station 120.0 inches aft of datum. What is the new CG?

Accepted Answer

94.6 inches

Answer

New weight = 3,150 lb; Moment removed = 50×120 = 6,000; New moment = (3,200×95) – 6,000 = 298,000; CG = 298,000÷3,150 ≈ 94.6 inches.

Question 2

What is 'zero fuel weight'?

Accepted Answer

Maximum allowable weight with no usable fuel on board

Answer

Zero fuel weight is the maximum certificated weight of the aircraft without usable fuel, establishing structural limits for wing bending loads.

Question 3

When fuel is burned during flight, how does the CG typically shift in a high-wing aircraft with wing tanks?

Accepted Answer

CG moves forward

Answer

In most high-wing designs, wing fuel is located forward of the CG, so as fuel burns off, the CG moves forward.

Question 4

The term 'useful load' is defined as the difference between:

Accepted Answer

Maximum gross weight and basic empty weight

Answer

Useful load = Maximum Gross Weight – Basic Empty Weight, and represents the total payload the aircraft can carry.

Question 5

A helicopter weight and balance calculation differs from a fixed-wing calculation primarily because helicopters must also consider:

Accepted Answer

Lateral CG limits in addition to longitudinal CG

Answer

Helicopters have both longitudinal and lateral CG limits due to the need for cyclic trim authority, making lateral balance critical.

(ACS) Airman Certification Standard Certified Mechanic Practice Test