Aircraft Weight and Balance Flashcards

An aircraft has an empty weight of 1,650 lbs with a CG at 87.0 inches. After adding equipment weighing 30 lbs at 130 inches, what is the new CG?

Answer: 87.8 inches

New moment = (1,650 × 87) + (30 × 130) = 143,550 + 3,900 = 147,450; new weight = 1,680; CG = 147,450 ÷ 1,680 ≈ 87.8 inches.

What is the term for the distance between the datum and the CG of an item?

Answer: Moment arm

The moment arm is the horizontal distance from the datum to the center of gravity of an item, used to calculate its moment.

Which document establishes the forward and aft CG limits for a certificated aircraft?

Answer: Type Certificate Data Sheet (TCDS)

The Type Certificate Data Sheet (TCDS) issued by the FAA defines the approved CG range and weight limits for certificated aircraft.

When an aircraft's CG is too far AFT, the most likely hazard is:

Answer: Reduced longitudinal stability and possible unrecoverable stall

An aft CG reduces longitudinal stability, which can make pitch control difficult and may result in an unrecoverable stall or spin.

A useful load includes which of the following?

Answer: Crew, fuel, passengers, and cargo

Useful load is the difference between maximum gross weight and basic empty weight, and includes crew, usable fuel, passengers, and cargo.

What effect does fuel burn have on CG if fuel tanks are located forward of the CG?

Answer: CG shifts aft

Burning fuel from tanks located forward of the CG removes forward moment, causing the CG to shift aft.

A ballast of 15 lbs must be placed to move the CG 2 inches forward on a 1,500 lb aircraft. Where must the ballast be placed relative to the CG?

Answer: 200 inches forward of the CG

Using the formula: distance = (weight × CG shift) ÷ ballast weight = (1,500 × 2) ÷ 15 = 200 inches forward of CG.