General - Weight and Balance

When computing weight and balance, an airplane is considered to be in balance when

• The average moment arm of the loaded airplane falls within its CG range.

• All moment arms of the plane fall within CG range.

• The movement of the passengers will not cause the moment arms to fall outside the CG range.

If the reference datum line is placed at the nose of an airplane rather than at the firewall or some other location aft of the nose,

• All measurement arms will be in negative numbers.

• All measurement arms will be in positive numbers.

• Measurement arms can be either positive or negative numbers depending on the manufacturer's preference.

The useful load of an aircraft is the difference between

• The maximum takeoff weight and basic empty weight.

• Maximum ramp or takeoff weight as applicable, and zero fuel weight.

• (1) The weight of an aircraft with all seats filled, full baggage/cargo, and full fuel, and (2) aircraft weight with all seats empty, no baggage/cargo, and minimum operating fuel.

What tasks are completed prior to weighing an aircraft to determine its empty weight?

• Remove all items except those on the aircraft equipment list; drain fuel and hydraulic fluid.

• Remove all items on the aircraft equipment list; drain fuel, compute oil and hydraulic weight.

• Remove all items except those on the aircraft list; drain fuel and fill hydraulic reservoir.

As weighed, the total empty weight of an aircraft is 5,862 pounds with a moment of 885,957. However, when the aircraft is weighed, 20 pounds of potable water were on board at +84, and 23 pounds of hydraulic fluid were in a tank located at +101. What is the empty weight CG of the aircraft?

• 150.700

• 151.700

• 151.365

Answer explanation

When weighing an aircraft to find its empty weight, a full reservoir of hydraulic fluid is included, but the potable water is not part of the required equipment.

ITEM WEIGHT ARM MOMENT

Aircraft 5,842 151.13 885,957

Potable water 20(-)

84 1,680(-)

TOTAL 5,842 151.365 884,277

When the potable water is computed out of the empty weight, we find the new empty weight to be 5,842 pounds and the new empty weight CG is located at fuselage station 151.365.

Reference: FAA-H-8083-30

1. 1. Private aircraft are required by regulations to be weighed periodically.

2. 2. Private aircraft are required to be weighed after making any alteration.

3. Regarding the above statements,

• Neither 1 nor 2 is true.

• Only 1 is true.

• Only 2 is true.

When an empty aircraft is weighed, the combined net weight at the main gears is 3,540 pounds with an arm of 195.5 inches. At the nose gear, the net weight is 2,322 pounds with an arm of 83.5 inches. The datum line is forward of the nose of the aircraft. What is the empty CG of the aircraft?

• 151.1

• 155.2

• 146.5

Answer explanation

ITEM WEIGHT ARM MOMENT

Main wheels 3,540 195.5 692,070

Nose wheel 2,322 83.5 193,887

TOTAL 5,862 151.14 885,957

The empty weight of this aircraft is 5,862 pounds, and its empty-weight CG is located at fuselage station 151.14.

In the process of weighing an airplane toward obtaining the CG, the arms from the weighing points always extend

• Parallel to the centerline of the airplane.

• Straight forward from each of the landing gear.

• Directly from each weighing point to the others.

Improper loading of a helicopter which results in exceeding either the fore or aft CG limits is hazardous due to the

• Reduction or loss of effective cyclic pitch control.

• Coriolis effect being translated to the fuselage.

• Reduction or loss of effective collective pitch control.

Which of the following can provide the empty weight of an aircraft if the aircraft's weight and balance records become lost, destroyed, or otherwise inaccurate?

• Reweighing the aircraft.

• The applicable Aircraft Specification or Type Certificate Data Sheet.

• The applicable flight manual or pilot's operating handbook.