AD 2005-20-25 70 FR 59237

The FAA adopts a new airworthiness directive (AD) for certain The Cessna Aircraft Company (Cessna) Models 401, 401A, 401B, 402, 402A, 402B, 402C, 404, 411, 411A, 414, 414A, 421, 421A, 421B, 421C, 425, and 441 airplanes equipped with certain avionics bus circuit breaker switches. This AD requires you to inspect the avionics bus circuit breaker switch to determine the date code and replace any without a date code. This AD also imposes a 1,000-hour safe life limit on avionics bus circuit breaker switches with a date code earlier than 0434. This AD results from reports of smoke and a burning smell in the cockpit. We are issuing this AD to prevent failure of the avionics bus circuit breaker switch, which could result in smoke and a burning smell in the cockpit. This failure could lead to reduced ability to control the airplane.