The weight of an aircraft and its balance are extremely important for operating in a safe and efficient manner. When a manufacturer designs an aircraft and the Federal Aviation Administration (FAA) certifies it, the specifications identify the aircraft’s maximum weight and the limits within which it must balance. The weight and balance system commonly employed among aircraft consists of three equally important elements: the weighing of the aircraft, the maintaining of the weight and balance records, and the proper loading of the aircraft.
The maximum weight of an aircraft is based on the amount of lift the wings or rotors can provide under the operating conditions for which the aircraft is designed. For example, if a small general aviation (GA) airplane required a takeoff speed of 200 miles per hour (mph) to generate enough lift to support its weight, that would not be safe. Taking off and landing at lower airspeeds is certainly safer than doing so at higher speeds.
Aircraft balance is also a significant factor in determining if the aircraft is safe to operate. An aircraft that does not have good balance can exhibit poor maneuverability and controllability, making it difficult or impossible to fly. This could result in an accident, causing damage to the aircraft and injury to the people on board. Safety is the primary reason for concern about an aircraft’s weight and balance.
Another important reason for concern about weight and balance is the efficiency of the aircraft. Improper loading reduces the efficiency of an aircraft from the standpoint of ceiling, maneuverability, rate of climb, speed, and fuel consumption. If an airplane is loaded in such a way that it is extremely nose heavy, higher than normal forces are exerted at the tail to keep the airplane in level flight. The higher than normal forces at the tail create additional drag, which requires additional engine power and therefore additional fuel flow to maintain airspeed.
The most efficient condition for an aircraft is to have the point where it balances fall close to, or exactly at, the aircraft’s center of lift. If this were the case, little or no flight control force would be needed to keep the aircraft flying straight and level. In terms of stability and safety, however, this perfectly balanced condition might not be desirable.
- Aircraft Weight and Balance
- Need and Requirements for Aircraft Weighing
- Weight and Balance Terminology – Datum
- Weight and Balance Terminology – Arm
- Weight and Balance Terminology – Moment
- Weight and Balance Terminology – Center of Gravity
- Weight and Balance Terminology – Maximum Weight
- Weight and Balance Terminology – Empty Weight
- Weight and Balance Terminology – Useful Load
- Weight and Balance Terminology – Minimum Fuel
- Weight and Balance Terminology – Tare Weight
- Procedures for Weighing an Aircraft
- Procedures for Weighing an Aircraft – Weight and Balance Data
- Weight and Balance Equipment – Scales
- Weight and Balance Equipment – Spirit Level
- Weight and Balance Equipment – Plumb Bob
- Weight and Balance Equipment – Hydrometer
- Preparing an Aircraft for Weighing – Fuel System
- Preparing an Aircraft for Weighing – Oil System
- Preparing an Aircraft for Weighing – Other Considerations
- Preparing an Aircraft for Weighing – Weighing Points
- Preparing an Aircraft for Weighing – Center of Gravity Range
- Standard Weights Used for Aircraft Weight and Balance
- Loading an Aircraft for Flight
- Weight and Balance Extreme Conditions
- Equipment Change and Aircraft Alteration
- The Use of Ballast
- Loading Graphs and CG Envelopes
- Helicopter Weight and Balance – General Concepts
- Helicopter Weighing
- Weight and Balance— Weight-Shift Control Aircraft and Powered Parachutes
- Powered Parachutes
- Weight and Balance for Large Airplanes
- Mean Aerodynamic Chord
- Weight and Balance Records