Why is weight and balance critical for the 787?

Why is weight and balance critical for the 787?

• A. It affects stability, performance, systems functionality, and safe handling.
• B. It only affects fuel efficiency.
• C. It only affects landing speed.
• D. It has no effect on in-flight performance.

Answer: (A)

Weight and balance is about where the airplane’s mass sits along the longitudinal axis, which sets the center of gravity. On the 787, keeping the CG within the approved limits is essential because it directly influences how the airplane behaves, how it performs, and how its systems respond. If the aircraft is loaded too far forward, more nose-down tendency shows up in handling. Rotation on takeoff requires more elevator input, climb performance is reduced, and stall characteristics shift, often demanding more runway than expected. If the CG is too far aft, the airplane becomes more pitch-sensitive and harder to control in gusts; stability margins shrink, stick forces lighten, and the risk of overcontrol or tailplane/stall-related issues increases, especially during approach and landing. Weight and balance also affects performance across the flight. Heavier configurations raise stall speeds, increase takeoff and landing speeds, lengthen runway needs, and load the structure differently, which can alter the loads the wing and landing gear must carry. As fuel is burned, the CG shifts, so loading plans and in-flight weight and balance checks must account for this drift to maintain safe handling and adequate stability throughout the flight. Finally, the 787’s advanced flight control and systems rely on accurate weight and balance data to function correctly—trim, stability augmentation, and envelope protection all assume the aircraft is within its balanced limits. Keeping weight and balance within limits ensures stable, predictable performance and safe handling at all phases of flight.

Weight and balance is about where the airplane’s mass sits along the longitudinal axis, which sets the center of gravity. On the 787, keeping the CG within the approved limits is essential because it directly influences how the airplane behaves, how it performs, and how its systems respond.

If the aircraft is loaded too far forward, more nose-down tendency shows up in handling. Rotation on takeoff requires more elevator input, climb performance is reduced, and stall characteristics shift, often demanding more runway than expected. If the CG is too far aft, the airplane becomes more pitch-sensitive and harder to control in gusts; stability margins shrink, stick forces lighten, and the risk of overcontrol or tailplane/stall-related issues increases, especially during approach and landing.

Weight and balance also affects performance across the flight. Heavier configurations raise stall speeds, increase takeoff and landing speeds, lengthen runway needs, and load the structure differently, which can alter the loads the wing and landing gear must carry. As fuel is burned, the CG shifts, so loading plans and in-flight weight and balance checks must account for this drift to maintain safe handling and adequate stability throughout the flight.

Finally, the 787’s advanced flight control and systems rely on accurate weight and balance data to function correctly—trim, stability augmentation, and envelope protection all assume the aircraft is within its balanced limits. Keeping weight and balance within limits ensures stable, predictable performance and safe handling at all phases of flight.