SAIB: CE-09-42
Date: July 24, 2009
Introduction
This Special Airworthiness Information Bulletin (SAIB) is being issued to advise you 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 per Cessna service
bulletins MEB09-3 and SEB09-6 dated May 11, 2009.
At this time, this airworthiness concern is not considered an unsafe condition that would warrant an
airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR part
39).
Background
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.
Recommendations
The FAA recommends that owners, operators, and maintenance technicians do the actions of the
above-referenced service bulletins within the next 400 hours of operation, 12 months, or the next
annual inspection, whichever comes first.
