The FAA’s handling of the Cessna twins spar issue has been a bumpy road, with a string of ADs already out, and concern from some owners’ groups over cost and practicality. Bob Vila, president of the Cessna Twins Spar Corporation (CTSC), says the AD could extend to all Cessna twins, and raises issues important to all owners of aging aircraft. “CTSC believes that the FAA, in the interest of better knowledge of aging aircraft/fatigue issues with the Cessna 400 aircraft, should fund a neutral third party such as the National Institute for Aging Aircraft (NIAR) to conduct a Cessna 400-series study,” Vila said in written comments he sent to AVweb yesterday. The current testing methods used by Cessna match 402 wings with a very stiff 425 fuselage, Vila said, which skews the results. “Cessna’s proprietary methods and data are not available for peer review and many have questioned their findings as a matter of logic and of a conflict of interest,” Vila said. “The Cessna study is apparently unable to predict spar cracking in the real world of real airplanes, as demonstrated by this extreme spar failure in an area not predicted by Cessna and that no cracks have been detected in the stations predicted by Cessna.” Despite those disagreements over how best to handle the matter, Vila supports the latest AD. “Due to the potential safety of flight and resulting loss of life that could result from this spar issue, demonstrated by actual cracks in actual aircraft, CTSC supports the FAA’s decision to issue this Emergency AD,” he said
