wing are rapidly changing direction, there is no opportunity  to reestablish laminar airflow across the wing.  This rotational momentum can pull the nose down into a  number of increasingly worse situations, depending on the  severity of the whip stall.  Figure 2-37  shows a whip stall and  the phases that can result, depending on the severity. Phase 1—Minor whip stall results in a nose-down pitch  attitude at which the nose is at a positive AOA and the  positive stability raises the nose to normal fl ight, as  described in  Figure 2-25C . Phase 2—If the rotational movement is enough to  produce a vertical dive, as illustrated in  Figure 2-29, the aerodynamic dive recovery might raise the nose  to an attitude to recover from the dive and resume  normal fl ight condition. Phase 3—The rotational momentum is enough to bring  the nose significantly past vertical (the nose has tucked  under vertical), but could still recover to a vertical dive  and eventually resume a normal fl ight condition. Phase 4—The rotational momentum is severe enough  to continue rotation, bringing the WSC wing into a  tumble from which there is no recovery to normal  flight, and structural damage is probable. Avoidance and emergency procedures are covered in Chapter  6, Basic Flight Maneuverers, and Chapter 13, Abnormal and  Emergency Procedures.  Similar to airplanes, sailplanes, and PPCs, increasing weight  creates increases in speed and descent rate. However, the  WSC aircraft has a unique characteristic. Adding weight to  a WSC aircraft creates more twist in the wing because the  outboard leading edges flex more. With less lift at the tips, a  nose-up effect is created and the trim speed lowers.  Therefore, adding weight can increase speed similar to other  aircraft, but reduce the trim speed because of the increased  twist unique to the WSC aircraft. Each manufacturer’s  make/model has different effects depending on the specifi c  design. As described in the Pilot’s Handbook of Aeronautical  Knowledge, the stall speed increases as the weight or loading  increases so some manufacturers may have specifi c carriage/ wing hang point locations for different weights. Some require  CG locations to be forward for greater weights so the trim  speed is well above the stall speed for the wing.  WSC aircraft have the same forces as airplanes during normal  coordinated turns. Greater bank angles result in greater  resultant loads. The flight operating strength of an aircraft  is presented on a graph whose horizontal scale is based on  load factor. The diagram is called a VG diagram—velocity  versus “G” loads or load factor. Each aircraft has its own VG  diagram which is valid at a certain weight and altitude. See  the Pilot’s Handbook of Aeronautical Knowledge for more  details on the VG diagram. Load factors are also similar to  the VG diagram applicable to WSC. The WSC aircraft propeller principles are similar to those  found in the Pilot’s Handbook of Aeronautical Knowledge,  except there is no “corkscrewing effect of the slipstream”  and there is less P-factor because the carriage is generally  fl ying with the thrust line parallel to the relative wind. The  wing acts independently, raising and lowering the AOA and  speed. This was introduced at the beginning of this chapter  when angle of incidence was defi ned.  The torque reaction does have a noticeable effect on the WSC  aircraft. With the typical left hand turn tendency (for right  hand turning propellers), turns are not typically built into the  wing. As in airplanes, some cart designs point the engine  down and to the right. Others do not make any adjustment, and  the pilot accounts for the turning effect through pilot input. It should be noted that many of the two-stroke propellers turn  to the right, as do conventional airplanes. However, many  four-stroke engine propellers turn to the left, creating a right  hand turn. Consult the POH for the torque characteristics of  your specifi c aircraft. Basic principles of aerodynamics apply to all aircraft;  however, the unique design of the wing and the separate  fuselage/carriage provide a simplistic and effi cient aircraft.  The following provide a summary of the unique aerodynamics  for the WSC wing: •  The WSC wing is pitch stable without a tail because  of the combination of airfoil design from root to tip,  sweep, twist, and planform. •  WSC wing flexibility allows the wing to twist from  side to side by shifting the weight providing the control  to roll the aircraft without control surfaces. •  The WSC wing only has two axes of control, pitch  and roll, while no yaw control is needed because it is  yaw stable. •  The WSC wing is stall resistant because under normal  flight conditions the tip chord is still flying while the  rest of the wing is stalled—similar to the airplane  canard system. Chapter Summary  Weight, Load, and Speed   Basic Propeller Principles 2-20