SPC Weight and Balance

Question 1

What is the 'datum' used in aircraft weight and balance calculations?

Accepted Answer

An imaginary vertical plane from which all arm measurements are taken

Answer

The datum is an imaginary vertical reference plane chosen by the manufacturer from which all horizontal distances (arms) are measured for weight and balance purposes.

Question 2

How is 'moment' calculated in weight and balance?

Accepted Answer

Weight multiplied by arm

Answer

Moment equals weight multiplied by arm (Moment = Weight × Arm), and it represents the turning force of that weight about the datum.

Question 3

What does an aircraft's 'empty weight' typically include?

Accepted Answer

Airframe, engine, unusable fuel, and full engine oil

Answer

Standard empty weight includes the airframe, engines, all permanently installed equipment, unusable fuel, and full engine oil as specified in the POH.

Question 4

What is 'useful load'?

Accepted Answer

The maximum gross weight minus the basic empty weight

Answer

Useful load is the difference between maximum allowable gross weight and the aircraft's basic empty weight, representing what the pilot can add (fuel, passengers, cargo).

Question 5

What happens to aircraft handling if the center of gravity (CG) is located too far forward?

Accepted Answer

The aircraft becomes nose-heavy and requires excessive back pressure to rotate

Answer

A forward CG makes the aircraft nose-heavy, requiring more elevator back pressure to maintain level flight and to rotate for takeoff, which can make rotation difficult.

(SPC) Student Pilot Certificate Practice Test

(SPC) Student Pilot Certificate Practice Test

SPC Weight and Balance