FAA Flight Instructor Airplane (FIA)Performance, Weight and BalanceMedium
An airplane weighs 2,400 lb and is loaded within CG limits. During flight, a 200-lb passenger seated at station 37 moves aft to an empty seat at station 73. What is the resulting shift in the airplane's CG?
- A1.5 inches aft
- B3.0 inches aft
- C6.0 inches aft
- D36 inches aft
Show answer & explanationAnswer & explanation
Correct answer: B. 3.0 inches aft
CG shift = (weight moved × distance moved) ÷ total weight = (200 lb × 36 in) ÷ 2,400 lb = 7,200 ÷ 2,400 = 3.0 in aft.
Why the other options are wrong
- A. Divides by twice the total weight, halving the correct answer.
- C. Doubles the correct shift by mis-multiplying.
- D. Uses the distance moved directly as the CG shift, ignoring total weight.
Weight Shift Formula
Used to calculate how far the CG moves when a known weight is relocated within the aircraft, without recomputing the full weight and balance.
- CG shift = (weight moved × distance moved) ÷ total aircraft weight
- Also used to find how much weight must be moved a known distance to achieve a desired CG shift
- Distance moved = difference between old and new arm
Memory trick: Move the weight, share the load: shift equals (weight×distance)/total load.