Weight and Balance Principles Flashcards

The mean aerodynamic chord (MAC) is:

Answer: The chord of an imaginary rectangular wing with the same aerodynamic characteristics as the actual wing

MAC represents a wing chord with equal aerodynamic effect as the actual wing.

A CG at station 30 with a leading edge of MAC at station 20 and MAC length of 50 in is what percent MAC?

Answer: 20%

(30 − 20) ÷ 50 = 0.20, or 20% MAC.

The location of the datum is:

Answer: Chosen by the manufacturer and stated in the TCDS

The datum is an arbitrary reference plane set by the manufacturer.

Maximum zero fuel weight is the maximum weight of an aircraft:

Answer: With no usable fuel on board

It is the maximum permissible weight with all weight except usable fuel.

Compared with most airplanes, helicopter weight and balance is unique because:

Answer: Both longitudinal and lateral CG limits may apply

Helicopters often have lateral as well as longitudinal CG limits.

An aircraft weighs 2,000 lb with an arm of 85 in. What is its moment index if the moment is divided by 1,000?

Answer: 170

Moment is 170,000, and dividing by 1,000 gives an index of 170.

An engine oil capacity of 8 quarts at about 1.875 lb per quart adds approximately how much weight?

Answer: 15 lb

Oil weighs about 7.5 lb per gallon, so 8 qt × 1.875 lb ≈ 15 lb.