the fuselage centerline, there is an equal weight existing at  a corresponding location on the right. This may be upset  by unbalanced lateral loading. The position of the lateral  CG is not computed in all aircraft, but the pilot must be  aware that adverse effects arise as a result of a laterally  unbalanced condition. In an airplane, lateral unbalance occurs  if the fuel load is mismanaged by supplying the engine(s)  unevenly from tanks on one side of the airplane. The pilot  can compensate for the resulting wing-heavy condition by  adjusting the trim or by holding a constant control pressure.  This action places the aircraft controls in an out-of-streamline  condition, increases drag, and results in decreased operating  efficiency. Since lateral balance is addressed when needed in  the aircraft flight manual (AFM) and longitudinal balance is  more critical, further reference to balance in this handbook  means longitudinal location of the CG.  The forward CG limit is often established at a location that  is determined by the landing characteristics of an aircraft.  During landing, one of the most critical phases of flight,  exceeding the forward CG limit may result in excessive loads  on the nosewheel, a tendency to nose over on tailwheel type  airplanes, decreased performance, higher stalling speeds, and  higher control forces.  Flying an aircraft that is out of balance can produce increased  pilot fatigue with obvious effects on the safety and efficiency  of flight. The pilot’s natural correction for longitudinal  unbalance is a change of trim to remove the excessive control  pressure. Excessive trim, however, has the effect of reducing  not only aerodynamic efficiency but also primary control  travel distance in the direction the trim is applied.  Adverse balance conditions affect flight characteristics in  much the same manner as those mentioned for an excess  weight condition. It is vital to comply with weight and  balance limits established for all aircraft. Operating above  the maximum weight limitation compromises the structural  integrity of the aircraft and can adversely affect performance.  Stability and control are also affected by improper balance.  Loading in a nose-heavy condition causes problems in  controlling and raising the nose, especially during takeoff  and landing. Loading in a tail heavy condition has a serious  effect upon longitudinal stability, and reduces the capability  to recover from stalls and spins. Tail heavy loading also  produces very light control forces, another undesirable  characteristic. This makes it easy for the pilot to inadvertently  overstress an aircraft.  Limits for the location of the CG are established by the  manufacturer. These are the fore and aft limits beyond  which the CG should not be located for flight. These limits  are published for each aircraft in the Type Certificate Data  Sheet (TCDS), or aircraft specification and the AFM or  pilot’s operating handbook (POH). If the CG is not within the  allowable limits after loading, it will be necessary to relocate  some items before flight is attempted.  The actual location of the CG can be altered by many variable  factors and is usually controlled by the pilot. Placement of  baggage and cargo items determines the CG location. The  assignment of seats to passengers can also be used as a means  of obtaining a favorable balance. If an aircraft is tail heavy,  it is only logical to place heavy passengers in forward seats.  Fuel burn can also affect the CG based on the location of the  fuel tanks. For example, most small aircraft carry fuel in the  wings very near the CG and burning off fuel has little effect  on the loaded CG.  For some aircraft, both fore and aft CG limits may be  specified to vary as gross weight changes. They may also  be changed for certain operations, such as acrobatic flight,  retraction of the landing gear, or the installation of special  loads and devices that change the flight characteristics.  The aft CG limit is the most rearward position at which the  CG can be located for the most critical maneuver or operation.  As the CG moves aft, a less stable condition occurs, which  decreases the ability of the aircraft to right itself after  maneuvering or turbulence.  A restricted forward CG limit is also specified to assure  that sufficient elevator/control deflection is available at  minimum airspeed. When structural limitations do not limit  the forward CG position, it is located at the position where  full-up elevator/control deflection is required to obtain a high  AOA for landing.  In extreme cases, a CG location that is beyond the forward  limit may result in nose heaviness, making it difficult or  impossible to flare for landing. Manufacturers purposely  place the forward CG limit as far rearward as possible to  aid pilots in avoiding damage when landing. In addition to  decreased static and dynamic longitudinal stability, other  undesirable effects caused by a CG location aft of the  allowable range may include extreme control difficulty,  violent stall characteristics, and very light control forces  which make it easy to overstress an aircraft inadvertently.  Control  Effects of Adverse Balance  Stability  Stability and Center of Gravity  10-3 