SAIB Affects 100, 200, 300 Series Cessna Aircraft

The FAA has issued a Special Airworthiness Information Bulletin (SAIB) to advise pilots and owners of an airworthiness concern on mandatory replacement intervals of Cessna Landing Light, Beacon Light, and Taxi Light switches on Cessna 100, 200, and 300 series airplanes, specified in Cessna service bulletins MEB09-3 and SEB09-6 dated May 11, 2009.

Cessna 100, 200, and 300 series airplanes utilize switches in the Landing Light, Beacon Light, and Taxi Light circuits that have been reported failing in the field causing overheating and smoke in the cockpit. There have been reports of burned insulation on the wiring terminals to the switch. On at
least one occasion, there was a small fire in the cockpit. The failure in these applications can be attributed to contact erosion leading to irregular arcing and eventual failure of the switch. The contact erosion has been shown to occur after approximately 4,000 cycles of operation.

Cessna service bulletins SEB09-6 and MEB09-3, initial release, dated May 11, 2009, specify the following:

• An inspection to determine time-in-service for the switches.
• Replacement of switches that have been in service for four or more years with the month and year of the installation written on the new replacement switch.
• The month and year of the initial installation written on switches that have been in service for less than four years.

The FAA recommends that owners, operators, and maintenance technicians act on the above-referenced service bulletins within the next 400 hours of operation, 12 months, or the next annual inspection, whichever comes first.

File Photo

At this time, the FAA says this airworthiness concern is not considered a condition that would warrant an AD.

FMI: www.faa.gov