Apart from good flight performance, a plane en-route also needs proper balance, resilience, and ease of control. Meeting all of these requirements is a challenging goal for plane designers.
There are three main flight stages: take-off, flight, and landing. The flight itself, in turn, has four modes: horizontal flight, ascent, descent, and maneuvering. It is crucial for the plane to be balanced (i.e. to have its weight distributed evenly) during all these stages and modes.
What does this entail? Mathematically, balance is achieved when the total sum of all forces and moments impacting the plane equals zero. That is what the plane’s steering controls are for. What happens if a pilot fails to balance the plane? A look at the participants of the Red Bull Flugtag show makes it quite clear.
Lack of balance creates unstable aerodynamic forces and moments that may either re-balance the plane or, on the contrary, make it tilt even further.
The weight and balance system allows to allocate the passengers, luggage, and other cargo properly throughout the aircraft cabins and holds, ensuring ultimate safety and comfort.