CHI07CA023

The airplane was substantially damaged when it impacted the runway during landing. The pilot reported that he deployed full flaps during the right turn from base leg to final approach. He stated that upon rolling out of the turn on final, he realized that the flaps were not symmetrically deployed. He added that the right flap was full down, but the left flap was only partially down. He attempted to raise the flaps; however, they became jammed asymmetrically. He stated that "as I rolled out for the flare, the left wing stalled and dropped sharply. I attempted to add power which only temporarily lifted the left wing. With the right wing generating significant lift and the left wing not, a steep left turn and loss of control resulted." A post accident examination confirmed flap system continuity. In addition, the flap actuator motor operated when electrical power was applied. Impact damage precluded an exact measurement of the flap deflections and rigging. The pilot noted that he had experienced an asymmetric extension and jammed flap situation about 2 months prior to the accident. He reported that in that instance he had maintained additional airspeed on approach and landed safely. He reported that subsequent maintenance action had resolved the problem and he had not experienced any further flap problems until the accident flight.

The airplane was substantially damaged when it impacted the runway during landing. The pilot reported that he deployed full flaps during the right turn from base leg to final approach. He stated that upon rolling out of the turn on final, he realized that the flaps were not symmetrically deployed. He added that the right flap was full down, but the left flap was only partially down. He attempted to raise the flaps; however, they became jammed asymmetrically. He stated that "as I rolled out for the flare, the left wing stalled and dropped sharply. I attempted to add power which only temporarily lifted the left wing. With the right wing generating significant lift and the left wing not, a steep left turn and loss of control resulted." A post accident examination confirmed flap system continuity. In addition, the flap actuator motor operated when electrical power was applied. Impact damage precluded an exact measurement of the flap deflections and rigging. The pilot noted that he had experienced an asymmetric extension and jammed flap situation in September 2006. He reported that in that instance he had maintained additional airspeed on approach and landed safely. Records indicated that on September 8, 2006, maintenance personnel "tightened the connections for the flap switch" and "neutralized the flaps [and] adjusted for level flight when extended." The most recent annual inspection was completed on September 1, 2006. During the inspection, the inboard flap hinge brackets were found to be loose and were tightened. Records related to the prior annual inspection dated August 1, 2005, noted that "the right flap was found to be 2 degrees lower that the left flap." The entry indicated that the flaps were rigged to neutral. He reported that he had not experienced any further flap problems after the maintenance until the accident flight.