Before flying, the pilot in command must determine the airplane is loaded within
its weight and balance limitations. The maximum weight for the airplane
must not be exceeded, and the weight must be distributed properly such that the
airplane is safely balanced for the flight.
Flying Over the Weight Limitations
Airplane's are designed with a maximum weight limitation. Operation above
this maximum weight limitation is illegal and unsafe for a number of reasons.
The structural design limitations of the aircraft take into account stresses that
the airplane could encounter. If the airplane is overloaded, the airplane
might be structurally damaged by rapid control movements, an encounter with
turbulence, or a hard landing. A damaged structural component of the
airplane might not be evident until spotted during a maintenance check or upon
failure of the component during a later flight. When a limitation is
exceeded, the pilot enters unknown territory. Structural damage or failure
is more likely, and performance is degraded and uncertain.
The manufacturer did not want to limit the load the airplane can carry. The
limitations were placed on the airplane because they are necessary for safety.
Effects of Weight
Whether and airplane is on the lighter or heavier side effects how it performs in
a number of ways.
Heavier weight means the wings must produce more lift to carry that weight.
The pilot has to maintain a higher angle of attack through all phases of flight
in order to produce the additional required lift. This means the airplane
flies closer to its stalling angle of attack throughout all phases of flight.
The higher angle of attack also produces more induced drag, resulting in a slower
cruise speed and higher fuel burn.
A heavy airplane accelerate more slowly during takeoff and must fly at a faster
airspeed to become airborne. Once in the air, the airplane will climb at a
slower rate and a shallower angle.
The landing performance is also affected. The heavier airplane must be
flown at a faster approach speed, resulting in a shallower approach angle or a
higher descent rate. Once on the ground, the airplane is more difficult to
Maneuverability is decreased in a heavier airplane, since it is harder to get a
heavier object to change directions.
Staying In the Limits
Weight can dramatically affect takeoff and landing performance, climb
performance, and fuel burn. It is a major factor in most performance
During preflight planning, you will learn how to use performance charts and table
to predict airplane performance. It is possible that some performance
factor will result in the airplane not being able to be loaded to it's certified
maximum takeoff weight. For example, if the takeoff were to be performed
at high altitude, on a short runway, or on a hot day. Perhaps there are
obstructions or terrain nearby the airport.
If the airplane is unable to safely carry the planned load, the load must be
reduced by leaving behind baggage or passengers. Another alternative is to
take a lighter fuel load and plan an additional fuel stop. If possible,
avoid this situation by planning ahead. Use the most suitable airports and
realistically plan for airplane performance. Inform your passengers of
baggage limitations and enforce those limitations.
Staying in the limits means flying stays safe and fun.