The flight controls primarily affect the pitch-and-roll axes.  Since there is no vertical tail plane, there is minimal or no  yaw control. Unlike in an airplane, the CG experienced by  the WSC aircraft wing remains constant. Since the weight  of the airframe acts through a single point (the wing attach  point), the range over which the weight may act is fixed at  the pendulum arm or length. Even though weight decreases  as fuel is consumed, weight remains focused at the wing  attach point. Because the range is fixed, there is no need to  establish a calculated range. The pilot should consult the  POH or Aircraft Operating Instructions (AOI) for maximum  takeoff weight and minimum and maximum seat weight  limits prior to each flight Every student pilot is taught how to work a weight and  balance problem and that it is important to make sure  every flight is loaded “within the envelope” (no more than  maximum gross weight) for both takeoff and landing. But  does he or she really understand just why this is so and the  disastrous effect of being out of the envelope? Two examples  of documented cases are provided below in an effort to  indicate the serious nature of maintaining the proper weight  and balance. In case studies when weight and balance was  listed as the major factor of the accident, many were fatal.  For instance, a small aircraft was loaded with hunters, gear,  and dogs (none of the dogs were secured inside the aircraft).  During takeoff, all the dogs went to the aft of the airplane.  This shifted the CG well aft of its allowable limit. The  airplane stalled and crashed. The airplane was destroyed  with casualties. Another accident occurred when a group of skydivers were  sitting on the floor toward the aft portion of the airplane  (they were unsecured). During takeoff, the CG was again  well beyond its aft limit. The airplane stalled and crashed.  The airplane was destroyed with casualties. Roll control on a powered parachute is achieved by changing  the shape of the wing. The change is achieved by varying  the length of steering lines attached to the outboard trailing  edges of the wing. The trailing edge of the parachute is pulled  down slightly on one side or the other to create increased  drag along that side. This change in drag creates roll and  yaw, permitting the aircraft to be steered. There is a safety factor built into the formula for maximum  gross weight. Any airplane can fly when it takes off at a  weight greater than maximum gross weight if the runway  is long enough and the density altitude is low enough.  However, landing is a different matter. All airplanes are built  to withstand an occasional hard landing, but what would  happen if the hard landing were combined with a substantially  overweight airplane? Something would probably break at that  time or the structure would be weakened enough to break  sometime in the future when everything might seem normal to  a pilot unaware of the previous situation. Even more disastrous  than an overweight, hard landing is reaching or exceeding  the structural integrity of the metal and/or composite design  values when maneuvering or when turbulence is encountered.  Hidden damage could result, causing an unexpected  catastrophic failure at some future time. The balloon is controlled by the pilot only in the vertical  dimension; this is in contrast to all other aircraft. He or she  achieves this control through the use of lift and weight.  Wind provides all other movement. The CG of the gondola  remains constant beneath the balloon envelope. As in WSC  and powered-parachute aircraft, there is no CG limitation. If an airplane is certificated with a maximum gross weight  of 6,000 pounds (its weight on the ground) and is rolled into  a 60° bank, the forces exerted make it feel as if it weighed  12,000 pounds. At its maximum certificated gross weight,  there is no problem because the aircraft is operated within its  certificated maneuvering loads. But loaded to 8,000 pounds  with a 60° bank or an abrupt pullup, it suddenly weighs  16,000 pounds and might not be able to perform! Even if it  could, there would probably be internal stress damage that  would show up on future flights Many pilots, from sport pilot to commercial pilot, tend to  underestimate the importance of proper weight and balance  of their aircraft. Load sheets are taken for granted and hasty  calculations are made of the aircraft’s CG. Unfortunately,  each year there are a number of accidents related to weight  and balance issues. Many of these occurrences could have  been avoided had more attention been given to weight and  balance. 1-6 Underestimating the Importance of  Weight and Balance Balloons Powered Parachutes The powered parachute is also a pendulum-style aircraft. Its  airframe CG is fixed at the pendulum attach point. It is more  limited in controllability than the WSC aircraft because it  lacks an aerodynamic pitch control. Pitch (and lift) control  is primarily a function of the power control. Increased power  results in increased lift; cruise power amounts to level flight; decreased power causes a descent. Due to this characteristic,  the aircraft is basically a one-airspeed aircraft. Once again,  because the CG is fixed at the attach point to the wing, there  is no CG range. As with WSC, the pilot should consult the  POH or AOI for maximum takeoff weight and minimum and  maximum seat weight limits prior to each flight