Weight and Balance

Question 1

What are the effects of a forward CG?

Answer 1

1. increased longitudinal stability
2. lower cruise speed
3. higher stall speed

Question 2

What are the effects of an aft CG?

Answer 2

1. decreased longitudinal stability
2. higher cruise speed
3. lower stall speed
4. poor stall/spin recovery

Question 3

Why does a forward CG cause a lower cruise speed?

Answer 3

• wing flies at higher AOA to create more lift to counter increased downward force by tail
• byproduct is increased induced drag

Question 4

What does a forward CG cause a higher stall speed?

Answer 4

• wing flies at higher AOA to create more lift to counter increased downward force by tail
• byproduct is increased induced drag

Question 5

Why does an aft CG cause a higher cruise speed?

Answer 5

• wing flies at a lower AOA due to decreased downward force by tail
• byproduct is decreased induced drag

Question 6

What is the reference datum?

Answer 6

• an imaginary vertical plane from which all measurements are taken

Question 7

What is the center of gravity?

Answer 7

• the point at which the airplane would balance if suspended by a string
• weight acts through the CG

Question 8

What is an arm?

Answer 8

• horizontal distance in inches from the reference staum to CG of an item

Question 9

What is a moment?

Answer 9

• weight multiplied by arm

- expressed in pound-inches

Question 10

What is a station?

Answer 10

• location on the airplane with a specific distance from the datum

Question 11

What is basic empty weight?

Answer 11

• weight of the standard airplane, optional equipment, unusable fuel, and full oil

Question 12

What is the payload?

Answer 12

• weight of occupants, cargo, or baggage

Question 13

What are standard weights?

Answer 13

• fuel = 6 lbs
• jet fuel = 6.8 lbs
• oil = 7.5 lbs
• water = 8.35 lbs

Question 14

What is the useful load?

Answer 14

• gross weight minus basic empty weight