Owners of Cessna 400-series twins are being urged to provide operating data in a last-ditch effort to mitigate the effects of potentially costly airworthiness directives (AD) requiring wing spar-cap modification. In March, the US Federal Aviation Administration agreed to delay issuing the ADs while industry collected additional information.
According to the US Aircraft Owners and Pilots Association (AOPA), operators are being asked to provide information on time in service, inspection status, operational profiles and other factors in an effort "to counter Cessna's engineering analysis that uses a single one-size-fits-all operational profile". The proposed ADs affect more 1,500 Cessna 401, 402, 411 and 414 aircraft, and require spar strap installations estimated to cost around $60,000.
AOPA and other opponents of the ADs argue that the manufacturer's analysis specifically looked at Cessna 402s in commercial service, and that aircraft in Part 91 private operation are likely to have less fatigue damage than those in Part 135 commercial operation. Spar-cap cracks have been discovered on six 402 series aircraft, and led to an in-flight wing separation on a 402C in April 1999. All were in commercial service.
Source: Flight International
