The Federal Aviation Admin. (FAA, Kansas City, Kan.) on Sept. 22 proposed a $2,425,000 (USD) civil penalty against general aviation aircraft manufacturer Cessna Aircraft Co. (Wichita, Kan.) in the wake of a incident in which a carbon composite wingskin partially detached from one of its Cessna Corvalis aircraft during flight. The Corvalis, a high-performance, four-seat single-engine general-aviation aircraft, features a significant number of composite parts, including primary structures. According to the agency’s press report, Cessna has 30 days from the receipt of the FAA’s enforcement letter to respond.
The incident occurred on Dec. 6, 2010, when an FAA test pilot, during a production-audit test flight in a Corvalis, observed a failure of the left wingskin. An approximately 7 ft/2.1m length of the skin separated from the load-bearing forward spar and damaged a fuel tank. The pilot made an emergency landing at the Independence, Kan., airport.
Subsequently, the FAA issued emergency airworthiness directives that grounded 13 Corvalis aircraft that were equipped with wings and other parts produced in Cessna’s Chihuahua, Mexico, plant between Dec. 17, 2009, and Dec. 16, 2010. FAA investigators determined that the incident did not arise from a failure (such as delamination) of the composite laminate but was, instead, a failure in an adhesive bond: The wingskin separated from the spar due to excessive humidity in the factory, which prevented the bonding material from curing properly. Further, the FAA alleges that Cessna failed to follow its FAA-approved quality-control system at its Chihuahua factory when it was manufacturing the wings and 82 other parts on the damaged airplane. Reportedly, the manufacturer has since made improvements to the plant.
“Safety is our highest priority,” said U.S. Transportation Secretary Ray LaHood, explaining, “We want to ensure that manufacturers are vigilant when it comes to aviation safety. There can be no exceptions.”