Weight and Balance

Question 1

Define “Empty weight” (FAA-H-8083-1, FAA-H-8083-25)

Answer 1

1. The weight of the airframe, engines, all permanently installed equipment, and unusable fuel (Depending on the FARs under which the aircraft was certificated, either the undrainable oil or full reservoir of oil is included)

Question 2

Define “Gross weight” (FAA-H-8083-1, FAA-H-8083-25)

Answer 2

1. The maximum allowable weight of the airplane and its contents

Question 3

Define “Useful load” (FAA-H-8083-1, FAA-H-8083-25)

Answer 3

1. The weight of the crew, passengers, baggage, usable fuel and drainable oil

Question 4

Define “Arm” (FAA-H-8083-1, FAA-H-8083-25)

Answer 4

1. The distance of the center of gravity of an item, from the datum line (measured in inches)

Question 5

Define “Moment” (FAA-H-8083-1, FAA-H-8083-25)

Answer 5

1. The weight of an item multiplied by its arm (Moments are expressed in pound-inches)

Question 6

Define “Center of gravity” (FAA-H-8083-1, FAA-H-8083-25)

Answer 6

1. The point from which an aircraft would balance from a string (Expressed in inches from datum)

Question 7

Define “Datum” (FAA-H-8083-1, FAA-H-8083-25)

Answer 7

1. An imaginary vertical plane from which all measurements of arm are taken (Established by the manufacturer)

Question 8

What performance characteristics will be adversely affected when an aircraft has been overloaded? (FAA-H-8083-1)

Answer 8

1. Longer takeoff roll
2. Reduced rate and angle of climb
3. Reduced maneuverability and higher stalling speed
4. Higher landing speed and longer landing roll

Question 9

What effect does a forward center of gravity have on an aircraft’s flight characteristics? (FAA-H-8083-1)

Answer 9

1. Higher stall speed
2. Slower cruise speed (greater angle of attack is required to maintain altitude)
3. More stable (the center of gravity is farther forward from the center of pressure which increases longitudinal stability)
4. Greater back elevator pressure required

Question 10

What effect does a rearward center of gravity have on an aircraft’s flight characteristics? (FAA-H-8083-1)

Answer 10

1. Lower stall speed
2. Higher cruise speed (smaller angle of attack is required to maintain altitude)
3. Less stable (the center of gravity is closer to the center of pressure, causing longitudinal instability)

Question 11

What are the standard weights assumed for fluids when calculating weight and balance problems? (FAA-H-8083-25)

Answer 11

1. Gasoline 6 lbs/U.S. gal
2. Oil 7.5 lbs/U.S. gal
3. Water 8.35 lbs/U.S. gal