The flight instructor reported that, during a soft field takeoff with the student pilot at the flight controls, the airplane was in ground effect and yawed to the left with a high angle of attack. As the student was correcting, a wind gust from the right caused the airplane to drift left and put the airplane into a "cross controlled situation." The instructor attempted to assume control of the airplane, but the student pilot only heard his name and continued to fly the airplane. The instructor reported he was unable to overpower the student and became concerned that the airplane was not producing enough lift and would aerodynamically stall or spin. The instructor pushed forward hard on the yoke to prevent the stall, and the airplane impacted terrain 50 yards off the side of the runway about midfield. The airplane sustained substantial damage to the fuselage, left and right wings. The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The student pilot did not submit a written statement as requested. An airport's automated weather observation station, located 14 miles to the north east, reported that, about the time of the accident, the wind was from 210° at 8 knots and variable from 180° to 240°. The airplane was departing from runway 14. The Federal Aviation Administration's Airplane Flying Handbook, FAA-H-8083-3B, provides information and guidance in a section titled "Soft/Rough-Field Takeoff and Climb" which stated in part: The pilot must be aware that the correct takeoff procedure for soft fields is quite different from the takeoff procedures used for short fields with firm, smooth surfaces. To minimize the hazards associated with takeoffs from soft or rough fields, the pilot should transfer the support of the airplane's weight as rapidly as possible from the wheels to the wings as the takeoff roll proceeds by establishing and maintaining a relatively high AOA or nose-high pitch attitude as early as possible. The pilot should lower the wing flaps prior to starting the takeoff (if recommended by the manufacturer) to provide additional lift and to transfer the airplane's weight from the wheels to the wings as early as possible. After the airplane becomes airborne, the pilot should gently lower the nose with the wheels clear of the surface to allow the airplane to accelerate to VY, or VX if obstacles must be cleared. Immediately after the airplane becomes airborne and while it accelerates, the pilot should be aware that, while transitioning out of the ground effect area, the airplane will have a tendency to settle back onto the surface. An attempt to climb prematurely or too steeply may cause the airplane to settle back to the surface as a result of the loss of ground effect. During the transition out of the ground effect area, the pilot should not attempt to climb out of ground effect before reaching the sufficient climb airspeed, as this may result in the airplane being unable to climb further, even with full power applied. Therefore, it is essential that the airplane remain in ground effect until at least VX is reached.