The pilot of the aerial application helicopter explained that he flew around the cornfield to identify hazards to flight (wires, houses, terrain, features, etc.) and then began aerial application operations. About 50 acres into the aerial application, the pilot was conducting a turn and checking his GPS when the glare from the sun made it difficult to see. The pilot described that he then misjudged the helicopter’s clearance from power lines and the helicopter impacted one of the top wires on the powerline with right skid and application boom. The helicopter then impacted the ground and came to rest on its left side, seriously injuring the pilot and resulting in substantial damage to the main rotor system, engine mounts, fuselage, and tailboom. The pilot reported that there were no preaccident mechanical malfunctions or failures of the helicopter that would have precluded normal operation.