with its nose tilted down; if the CG is too far aft of the mast,  the nose tilts up.  [Figure 6-1] CG Forward of Forward Limit forward CG may occur when a heavy pilot and passenger  take off without baggage or proper ballast located aft of the  rotor mast. This situation becomes worse if the fuel tanks  are located aft of the rotor mast because as fuel burns the  CG continues to shift forward.  This condition is easily  recogniz ed when coming to a hover  following a vertical takeoff. The helicopter has a nose-low  attitude, and excessive rearward displacement of the cyclic  control is needed to maintain a hover in a no-wind condition.  Do not continue flight in this  condition, since a pilot could  rapidly lose rearward cyclic  control as fuel is consumed. A  pilot may also find it impossible to decelerate sufficiently to  bring the helicopter to a stop. In the event of engine failure  and the resulting autorotation, there may not be enough cyclic  control to flare properly for the landing. forward CG is not as obvious when hovering into a strong  wind, since less rearward cyclic d isplacement is required than  when hovering with no wind. When determining whether a  critical balance condition exists, it is essential to consider the  wind velocity and its relation to the rearward displacement  of the cyclic control. Without proper ballast in the cockpit, exceeding the aft CG  may occur when: A pilot can recognize the aft CG condition when coming  to a hover following a vertical takeoff. The helicopter will  have a tail-low attitude and will need excessive forward  displacement of cyclic control to maintain a hover in a no- wind condition. When facing upwind, even greater forward  cyclic is needed. If flight is continued in this condition, it may be impossible  to fly in the upper allowable airspeed range due to inadequate  forward cyclic authority to maintain a nose-low attitude. In  addition, with an extreme aft CG, gusty or rough air could  accelerate the helicopter to a speed faster than that produced  with full forward cyclic control. In this case, dissymmetry of  lift and blade flapping could cause the rotor disk to tilt aft.  With full forward cyclic control already applied, a pilot might  not be able to lower the rotor disk, resulting in possible loss  of control, or the rotor blades striking the tailboom. For smaller helicopters, it is generally unnecessary to  determine the lateral CG for normal flight instruction and  passenger flights. This is because helicopter cabins are  relatively narrow and most optional equipment is located  near the centerline. However, some helicopter manuals  specify the seat from which a pilot must conduct solo flight.  In addition, if there is an unusual situation that could affect  the lateral CG, such as a heavy pilot and a full load of fuel  on one side of the helicopter, its position should be checked  against the CG envelope. If carrying external loads in a  position that requires large lateral cyclic control displacement  to maintain level flight, fore and aft cyclic effectiveness could  be limited dramatically. Manufacturers generally account  for known lateral CG displacements by locating external  attachment points opposite the lateral imbalance. Examples  are placement of hoist systems attached to the side, and wing  stores commonly used on military aircraft for external fuel  pods or armament systems.  Lateral Balance CG Aft of Aft Limit •  A lightweight pilot takes off solo with a full load of  fuel located aft of the rotor mast. •  A lightweight pilot takes  off with maximum baggage  allowed in a baggage  compartment located aft of the  rotor mast. •  A lightweight pilot takes off with a combination of  baggage and substantial  fuel where both are aft of the  rotor mast. Figure 6-1.  The location of the CG strongly influences how the helicopter handles.  CG Directly Under The Rotor Mast Forward CG Aft CG CG CG CG 6-3