American Champion 7KCAB N5065X accident near Greeley, Colorado

Probable cause

An in-flight failure of the wing fabric for undetermined reasons.

NTSB analysis

The pilot was practicing steep turns around a point at 7,500 feet mean sea level. During one of the turns, he heard an unusual sound and saw something falling away from the aircraft. He then noticed a piece of fabric “flapping” in the slipstream at the trailing edge of the right aileron. The airplane developed a slight sink rate, but the engine and flight controls operated normally. He returned to the airport and made an uneventful landing. Postflight inspection disclosed that nearly 80 percent of the fabric on the top of the right wing had separated, and several ribs were damaged when the rivets separated with the fabric. Several other ribs were distorted from slipstream. The airplane had been used for spotting fish in Alaska. According to the maintenance records, the airframe was last recovered on July 21, 2003, at a total time of 3,894.0 hours. Fabric punch tests since the recovering had been satisfactory.

Text from the NTSB. Open the NTSB docket for CEN10LA198 for the full record.