How do you verify that the aircraft's CG is within permissible limits for a flight?

How do you verify that the aircraft's CG is within permissible limits for a flight?

• A. Weigh only the aircraft empty weight.
• B. CG is fixed at design and cannot be changed.
• C. Only verify fuel quantity; CG is not evaluated.
• D. Compute CG with planned payload and fuel; compare to manufacturer's CG envelope; adjust payload or fuel if outside.

Answer: (D)

Center of gravity is the balance point of the aircraft and it moves as you load the airplane. To verify it’s within limits, you must compute the CG for the actual or planned loading and compare it to the manufacturer’s CG envelope. Begin with the numbers you’ll actually carry: the empty weight and its moment, the planned payload (passengers, baggage, cargo) with their respective arm distances, and the planned fuel quantity with its arm. Add up the total weight and the total moment, then divide the total moment by the total weight to get the CG location. Compare that CG position to the manufacturer’s forward and aft limits. If it lies outside, adjust the loading—redistribute passengers or baggage or change fuel quantity—until the CG is within the envelope. This approach matters because the same airplane can have very different handling characteristics depending on where the weight sits. Incorrect CG can make the aircraft nose- or tail-heavy, affect stall behavior, stall speed, and control effectiveness, and reduce controllability. The other ideas fall short because they ignore how loading shifts the CG. Weighing only the empty aircraft ignores how passengers and bags change balance. Treating CG as fixed ignores fuel and payload movement. Focusing only on fuel quantity misses the influence of passengers and baggage on the balance.

Center of gravity is the balance point of the aircraft and it moves as you load the airplane. To verify it’s within limits, you must compute the CG for the actual or planned loading and compare it to the manufacturer’s CG envelope.

Begin with the numbers you’ll actually carry: the empty weight and its moment, the planned payload (passengers, baggage, cargo) with their respective arm distances, and the planned fuel quantity with its arm. Add up the total weight and the total moment, then divide the total moment by the total weight to get the CG location. Compare that CG position to the manufacturer’s forward and aft limits. If it lies outside, adjust the loading—redistribute passengers or baggage or change fuel quantity—until the CG is within the envelope.

This approach matters because the same airplane can have very different handling characteristics depending on where the weight sits. Incorrect CG can make the aircraft nose- or tail-heavy, affect stall behavior, stall speed, and control effectiveness, and reduce controllability.

The other ideas fall short because they ignore how loading shifts the CG. Weighing only the empty aircraft ignores how passengers and bags change balance. Treating CG as fixed ignores fuel and payload movement. Focusing only on fuel quantity misses the influence of passengers and baggage on the balance.