Free A&P Weight and Balance Control Questions and Answers — Questions and Answers
Question 1: An aircraft with a total weight of 2,100 pounds has a total moment of 96,600 in-lb. What is the location of its Center of Gravity (CG)?
- 46.0 inches aft of datum (Correct answer)
- 0.0217 inches aft of datum
- 2,003,400 inches aft of datum
- 50.5 inches aft of datum
Correct answer: 46.0 inches aft of datum
The Center of Gravity (CG) is calculated by dividing the total moment by the total weight. In this case, 96,600 in-lb divided by 2,100 lbs equals 46.0 inches.
Question 2: In the context of aircraft weight and balance, what is the 'datum'?
- The point at which the aircraft would balance if suspended.
- The specified forward and aft points within which the CG must be located.
- An imaginary vertical plane or line from which all horizontal measurements of arm are taken. (Correct answer)
- The weight of the aircraft including only standard equipment, unusable fuel, and full operating fluids.
Correct answer: An imaginary vertical plane or line from which all horizontal measurements of arm are taken.
The datum is an imaginary vertical reference plane established by the manufacturer from which all horizontal distances (arms) are measured for weight and balance purposes.
Question 3: Which of the following scenarios would cause the most significant change to an aircraft's center of gravity?
- Burning 60 pounds of fuel from main tanks located very close to the existing CG.
- A 200-pound passenger moving from a rear seat (STA 150) to a front seat (STA 70). (Correct answer)
- Adding 20 pounds of oil to the engine at station -15.
- Removing a 40-pound survival kit from the forward baggage compartment at station 30.
Correct answer: A 200-pound passenger moving from a rear seat (STA 150) to a front seat (STA 70).
The greatest change in CG occurs when the largest weight is shifted over the greatest distance. A 200-pound passenger moving 80 inches (150 - 70) creates a moment change of 16,000 in-lb, which is significantly larger than the moment changes in the other options.
Question 4: When preparing an aircraft for weighing to determine its empty weight, what is the standard procedure regarding the fuel in the tanks?
- The tanks must be completely full to ensure a known quantity.
- The fuel level is irrelevant as long as its volume is documented.
- The tanks must be completely empty, including all unusable fuel.
- The fuel must be drained until only the unusable supply remains. (Correct answer)
Correct answer: The fuel must be drained until only the unusable supply remains.
Standard procedure for determining empty weight requires draining the fuel system until only the unusable fuel remains. The weight of unusable fuel is part of the aircraft's empty weight. Alternatively, tanks can be full and the weight of usable fuel can be subtracted, but draining to unusable is the standard method.
Question 5: A helicopter is loaded with its center of gravity at the aft limit. During a long flight, fuel is consumed from a main tank located forward of the CG. How will this affect the helicopter's CG and handling?
- The CG will shift forward, improving stability.
- The CG will remain unchanged because fuel is a consumable weight.
- The CG will shift aft, potentially exceeding the aft limit and reducing stability. (Correct answer)
- The CG will shift aft initially, then forward as the tank empties.
Correct answer: The CG will shift aft, potentially exceeding the aft limit and reducing stability.
Removing weight (burning fuel) from a location forward of the center of gravity will cause the CG to shift aft. If the helicopter was already at its aft limit, this shift could move the CG beyond the approved range, leading to instability and control difficulties.
Question 6: What is the definition of 'Maximum Zero Fuel Weight' (MZFW)?
- The maximum authorized weight of the aircraft for takeoff.
- The weight of the aircraft with no passengers, cargo, or fuel.
- The maximum permissible weight of a loaded aircraft (crew, passengers, cargo) before usable fuel is added. (Correct answer)
- The maximum weight permitted for landing.
Correct answer: The maximum permissible weight of a loaded aircraft (crew, passengers, cargo) before usable fuel is added.
Maximum Zero Fuel Weight is a structural limitation. It is the maximum weight allowed for the aircraft and its contents (crew, passengers, baggage, and cargo) before the weight of usable fuel is added. Any weight added above the MZFW must be fuel.
Free A&P Weight and Balance Control Questions and Answers
An aircraft with a total weight of 2,100 pounds has a total moment of 96,600 in-lb.
What is the location of its Center of Gravity (CG)?