Airworthiness Directives; Cessna Aircraft Company Models 401, 401A, 401B, 402, 402A, 402B, 411, and 411A Airplanes

The FAA is adopting a new airworthiness directive (AD) to supersede AD 79-10-15, which applies to all Cessna Aircraft Company (Cessna) Models 401, 401A, 401B, 402, 402A, 402B, 411, and 411A airplanes. AD 79-10-15 currently requires repetitive inspections of the right and left wing spar lower cap areas for fatigue cracks and requires wing spar cap repair or replacement as necessary. This AD is the result of fatigue and crack growth analyses of the wings of these airplanes, recent cracks found on similar design Model 402C airplanes, and the FAA's determination that repetitive inspections and a wing spar modification are necessary to address the unsafe condition. Consequently, this AD would require repetitive inspections and a spar strap modification on each wing. The actions specified by this AD are intended to prevent wing spar cap failure caused by undetected fatigue cracks. Such failure could result in loss of a wing with consequent loss of airplane control. FAA is also issuing AD 2005-12-13 to require the spar strap modification and long-term inspections on Models 402C and 414A airplanes.