A&P Weight and Balance Principles Questions and Answers — Questions and Answers
Question 1: An aircraft is loaded such that its center of gravity (CG) is located at the most forward limit. Which of the following performance characteristics is to be expected?
- A lower cruising speed and a higher stalling speed. (Correct answer)
- A higher cruising speed and a lower stalling speed.
- Improved stall recovery characteristics and increased fuel efficiency.
- Reduced longitudinal stability and a lower angle of attack for level flight.
Correct answer: A lower cruising speed and a higher stalling speed.
A forward CG requires greater back pressure on the elevator controls to maintain level flight. This results in flying with a higher angle of attack, which increases induced drag. The increased drag leads to a lower cruising speed, and the higher angle of attack means the aircraft is closer to its critical angle of attack, resulting in a higher stalling speed.
Question 2: A technician needs to calculate the center of gravity (CG) of an aircraft. The total weight is 3,500 lbs and the total moment is 297,500 in-lbs. What is the correct formula and resulting CG location?
- CG = Total Weight / Total Moment; 0.0117 inches
- CG = Total Moment x Total Weight; 1,041,250,000 inches
- CG = Total Moment / Total Weight; 85 inches (Correct answer)
- CG = Total Weight + Total Moment; 301,000 inches
Correct answer: CG = Total Moment / Total Weight; 85 inches
The correct formula to find the Center of Gravity (CG) is to divide the total moment by the total weight. In this scenario: CG = 297,500 in-lbs / 3,500 lbs = 85 inches. The CG is located 85 inches from the datum.
Question 3: Which term is defined as the empty weight of the aircraft plus the weight of optional and special equipment that has been installed?
- Useful Load
- Basic Empty Weight (Correct answer)
- Payload
- Maximum Zero Fuel Weight
Correct answer: Basic Empty Weight
Basic Empty Weight includes the standard empty weight (airframe, engines, permanently installed equipment, unusable fuel, and full operating fluids) plus the weight of any installed optional or special equipment.
Question 4: During a weight and balance procedure, a technician calculates that a 50 lb piece of equipment needs to be moved to shift the aircraft's CG forward by 2 inches. If the total aircraft weight is 4,000 lbs, how far must the equipment be moved?
- Forward by 80 inches
- Aft by 160 inches
- Aft by 80 inches
- Forward by 160 inches (Correct answer)
Correct answer: Forward by 160 inches
The formula for weight shifting is: Distance to Move = (Total Weight x CG Change) / Weight Shifted. Plugging in the values: Distance = (4,000 lbs x 2 inches) / 50 lbs = 160 inches. To move the CG forward, the equipment must also be moved forward.
Question 5: Which of the following defines the imaginary vertical plane from which all horizontal measurements of arm are taken for weight and balance purposes?
- Center of Gravity (CG)
- Mean Aerodynamic Chord (MAC)
- Longitudinal Axis
- Datum (Correct answer)
Correct answer: Datum
The Datum is an imaginary vertical plane or line established by the manufacturer from which all horizontal distances (arms) are measured for weight and balance calculations. Its location is specified in the aircraft's Type Certificate Data Sheet (TCDS) or flight manual.
Question 6: An aircraft is loaded with its center of gravity (CG) near the aft limit. What effect does this have on the aircraft's stability and stall recovery characteristics?
- Longitudinal stability is increased, making stall recovery easier.
- Directional stability is decreased, but stall recovery is unaffected.
- Longitudinal stability is reduced, making stall recovery more difficult. (Correct answer)
- Longitudinal stability is unaffected, but stall recovery is more difficult.
Correct answer: Longitudinal stability is reduced, making stall recovery more difficult.
An aft CG reduces longitudinal stability because the arm between the CG and the tail's stabilizing force is shorter. This makes the aircraft less stable and more difficult to control. In a stall, the reduced stability can make it harder, or even impossible, to lower the nose and recover.
A&P Weight and Balance Principles Questions and Answers
An aircraft is loaded such that its center of gravity (CG) is located at the most forward limit.
Which of the following performance characteristics is to be expected?