Weight and Balance
Regulations requires establishment of the ranges of weights and CGs within which an aircraft may be operated safely. The manufacturer provides this information, which is included in the approved AFM, TCDS, or aircraft specifications.
Weight
Excessive weight reduces the flight performance in almost every respect. For example, the most important performance deficiencies of an overloaded aircraft are:
- Higher takeoff speed
- Longer takeoff run
- Reduced rate and angle of climb
- Lower maximum altitude
- Shorter range
- Reduced cruising speed
- Reduced maneuverability
- Higher stalling speed
- Higher approach and landing speed
- Longer landing roll
- Excessive weight on the nose wheel or tail wheel
Balance (or CG)
The CG is a point at which the aircraft would balance if it were suspended at that point.
Note that the center of lift of the wings (where the lift force is being applied), is always aft of your CG, when loaded within limits. The tail is providing a downward force which counteracts the torque created by the main wing.
A CG that is too far forward can:
- Make it impossible to flare for landing, in extreme cases
- Increase induced drag needed for level flight, and decrease cruise performance
- This is due to the increase of the tail downforce, which in turn requires a high angle of attack to counteract
A CG that is too far aft can:
- Produce very light control forces
- Can limit the ability to recover from stalls or spins
- Decrease induced drag needed for level flight, and actually increase cruise performance