A forward CG may occur when a heavy pilot and pas- senger 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 weight located aft of the rotor mast becomes less. repairs or alterations must be recorded by a certified mechanic. When the revised weight and moment are recorded on a new form, the old record is marked with the word “superseded” and dated with the ef fective date of the new record. This makes it easy to determine which weight and balance form is the latest version. You must use the latest weight and balance data for computing all loading problems. You can recognize this condition when coming to a hover following a vertical takeoff. The helicopter will have a nose-low attitude, and you will need excessive rearward displacement of the cyclic control to maintain a hover in a no-wind condition. You should not continue flight in this condition, since you could rapidly run out of rearward cyclic control as you consume fuel. You also may find it impossible to decelerate sufficiently to bring the helicopter to a stop. In the event of engine failure and the resulting autorotation, you may not have enough cyclic control to flare properly for the landing. Helicopter performance is not only affected by gross weight, but also by the position of that weight. It is essential to load the aircraft within the allowable center- of-gravity range specified in the rotorcraft flight man- ual’s weight and balance limitations. CENTER OF GRAVITY (CG) The center of gravity is defined as the theoretical point where all of the aircraft’s weight is considered to be concentrated. If a helicopter was suspended by a cable attached to the center-of-gravity point, it would balance like a teeter-totter. For helicopters with a single main rotor, the CG is usually close to the main rotor mast. A forward CG will not be as obvious when hovering into a strong wind, since less rearward cyclic displacement is required than when hovering with no wind. When deter- mining 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: Improper balance of a helicopter’s load can result in serious control problems. The allowable range in which the CG may fall is called the “CG range.” The exac CG location and range are specified in the rotorcraft flight manual for each helicopter. In addition to making a helicopter difficult to control, an out-of-balance load- ing condition also decreases maneuverability since cyclic control is less effective in the direction opposite to the CG location. Ideally, you should try to perfectly balance a helicopter so that the fuselage remains horizontal in hovering flight, with no cyclic pitch control needed except for wind correction. Since the fuselage acts as a pendulum suspended from the rotor, changing the center of grav- ity changes the angle at which the aircraft hangs from the rotor. When the center of gravity is directly under the rotor mast, the helicopter hangs horizontal; if the CG is too far forward of the mast, the helicopter hangs with its nose tilted down; if the CG is too far aft of the mast, the nose tilts up. [Figure 7-1] You can recognize the aft CG condition when coming to a hover following a vertical takeoff. The helicopter will have a tail-low attitude, and you will need exces- 7-2 Figure 7-1. The location of the center of gravity strongly influences how the helicopter handles. F orw ard CGGLYPH<.notdef> CG Directly Under The Rotor MastGLYPH<.notdef> Aft CGGLYPH<.notdef> • A lightweight pilot takes off with a combination of baggage and substantial fuel where both are aft of the rotor mast. • A lightweight pilot takes off with maximum bag- gage allowed in a baggage compartment located aft of the rotor mast. • A lightweight pilot takes off solo with a full load of fuel located aft of the rotor mast. CG FORWARD OF FORWARD LIMIT BALANCE CG AFT OF AFT LIMIT